From 8183c71e787f5ae4b78d40c2a82b83c335e9b65e Mon Sep 17 00:00:00 2001
From: Adrien Crivelli <adrien.crivelli@gmail.com>
Date: Tue, 31 Oct 2017 19:58:46 +0900
Subject: [PATCH] Remove duplicated declarations of interface implementation

---
 src/PhpSpreadsheet/Calculation/Calculation.php       | 4 ++--
 src/PhpSpreadsheet/Reader/Csv.php                    | 2 +-
 src/PhpSpreadsheet/Reader/Gnumeric.php               | 2 +-
 src/PhpSpreadsheet/Reader/Html.php                   | 2 +-
 src/PhpSpreadsheet/Reader/IReader.php                | 5 +++++
 src/PhpSpreadsheet/Reader/Ods.php                    | 2 +-
 src/PhpSpreadsheet/Reader/Slk.php                    | 2 +-
 src/PhpSpreadsheet/Reader/Xls.php                    | 2 +-
 src/PhpSpreadsheet/Reader/Xlsx.php                   | 2 +-
 src/PhpSpreadsheet/Reader/Xml.php                    | 2 +-
 src/PhpSpreadsheet/Style/Alignment.php               | 3 +--
 src/PhpSpreadsheet/Style/Border.php                  | 3 +--
 src/PhpSpreadsheet/Style/Borders.php                 | 3 +--
 src/PhpSpreadsheet/Style/Color.php                   | 3 +--
 src/PhpSpreadsheet/Style/Fill.php                    | 3 +--
 src/PhpSpreadsheet/Style/Font.php                    | 3 +--
 src/PhpSpreadsheet/Style/NumberFormat.php            | 3 +--
 src/PhpSpreadsheet/Style/Protection.php              | 3 +--
 src/PhpSpreadsheet/Style/Style.php                   | 3 +--
 src/PhpSpreadsheet/Style/Supervisor.php              | 4 +++-
 src/PhpSpreadsheet/Worksheet/CellIterator.php        | 2 +-
 src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php  | 2 +-
 src/PhpSpreadsheet/Worksheet/Drawing.php             | 3 +--
 src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php | 3 +--
 src/PhpSpreadsheet/Worksheet/MemoryDrawing.php       | 4 +---
 src/PhpSpreadsheet/Worksheet/RowCellIterator.php     | 2 +-
 src/PhpSpreadsheet/Writer/Csv.php                    | 4 ++--
 src/PhpSpreadsheet/Writer/Html.php                   | 2 +-
 src/PhpSpreadsheet/Writer/Ods.php                    | 4 ++--
 src/PhpSpreadsheet/Writer/Pdf.php                    | 2 +-
 src/PhpSpreadsheet/Writer/Pdf/Dompdf.php             | 3 +--
 src/PhpSpreadsheet/Writer/Pdf/Mpdf.php               | 3 +--
 src/PhpSpreadsheet/Writer/Pdf/Tcpdf.php              | 3 +--
 src/PhpSpreadsheet/Writer/Xls.php                    | 2 +-
 src/PhpSpreadsheet/Writer/Xlsx.php                   | 2 +-
 35 files changed, 44 insertions(+), 53 deletions(-)

diff --git a/src/PhpSpreadsheet/Calculation/Calculation.php b/src/PhpSpreadsheet/Calculation/Calculation.php
index 5dba73cf..6cf3b63f 100644
--- a/src/PhpSpreadsheet/Calculation/Calculation.php
+++ b/src/PhpSpreadsheet/Calculation/Calculation.php
@@ -40,14 +40,14 @@ class Calculation
     /**
      * Instance of this class.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Calculation
+     * @var Calculation
      */
     private static $instance;
 
     /**
      * Instance of the spreadsheet this Calculation Engine is using.
      *
-     * @var PhpSpreadsheet
+     * @var Spreadsheet
      */
     private $spreadsheet;
 
diff --git a/src/PhpSpreadsheet/Reader/Csv.php b/src/PhpSpreadsheet/Reader/Csv.php
index 09a6b6f7..5d6f1e98 100644
--- a/src/PhpSpreadsheet/Reader/Csv.php
+++ b/src/PhpSpreadsheet/Reader/Csv.php
@@ -6,7 +6,7 @@ use PhpOffice\PhpSpreadsheet\Cell\Cell;
 use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
-class Csv extends BaseReader implements IReader
+class Csv extends BaseReader
 {
     /**
      * Input encoding.
diff --git a/src/PhpSpreadsheet/Reader/Gnumeric.php b/src/PhpSpreadsheet/Reader/Gnumeric.php
index 5eb7f498..0b70da6b 100644
--- a/src/PhpSpreadsheet/Reader/Gnumeric.php
+++ b/src/PhpSpreadsheet/Reader/Gnumeric.php
@@ -18,7 +18,7 @@ use PhpOffice\PhpSpreadsheet\Style\Fill;
 use PhpOffice\PhpSpreadsheet\Style\Font;
 use XMLReader;
 
-class Gnumeric extends BaseReader implements IReader
+class Gnumeric extends BaseReader
 {
     /**
      * Shared Expressions.
diff --git a/src/PhpSpreadsheet/Reader/Html.php b/src/PhpSpreadsheet/Reader/Html.php
index 78850de5..44efa78a 100644
--- a/src/PhpSpreadsheet/Reader/Html.php
+++ b/src/PhpSpreadsheet/Reader/Html.php
@@ -14,7 +14,7 @@ use PhpOffice\PhpSpreadsheet\Style\Fill;
 use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
 
 /** PhpSpreadsheet root directory */
-class Html extends BaseReader implements IReader
+class Html extends BaseReader
 {
     /**
      * Sample size to read to determine if it's HTML or not.
diff --git a/src/PhpSpreadsheet/Reader/IReader.php b/src/PhpSpreadsheet/Reader/IReader.php
index cbb18a7d..e35c4ee6 100644
--- a/src/PhpSpreadsheet/Reader/IReader.php
+++ b/src/PhpSpreadsheet/Reader/IReader.php
@@ -4,6 +4,11 @@ namespace PhpOffice\PhpSpreadsheet\Reader;
 
 interface IReader
 {
+    /**
+     * IReader constructor.
+     */
+    public function __construct();
+
     /**
      * Can the current IReader read the file?
      *
diff --git a/src/PhpSpreadsheet/Reader/Ods.php b/src/PhpSpreadsheet/Reader/Ods.php
index e0437bc3..b183a4f2 100644
--- a/src/PhpSpreadsheet/Reader/Ods.php
+++ b/src/PhpSpreadsheet/Reader/Ods.php
@@ -17,7 +17,7 @@ use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 use XMLReader;
 use ZipArchive;
 
-class Ods extends BaseReader implements IReader
+class Ods extends BaseReader
 {
     /**
      * Create a new Ods Reader instance.
diff --git a/src/PhpSpreadsheet/Reader/Slk.php b/src/PhpSpreadsheet/Reader/Slk.php
index 362e437e..47dbab43 100644
--- a/src/PhpSpreadsheet/Reader/Slk.php
+++ b/src/PhpSpreadsheet/Reader/Slk.php
@@ -8,7 +8,7 @@ use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Style\Border;
 
-class Slk extends BaseReader implements IReader
+class Slk extends BaseReader
 {
     /**
      * Input encoding.
diff --git a/src/PhpSpreadsheet/Reader/Xls.php b/src/PhpSpreadsheet/Reader/Xls.php
index 8509dc05..ba8ddd27 100644
--- a/src/PhpSpreadsheet/Reader/Xls.php
+++ b/src/PhpSpreadsheet/Reader/Xls.php
@@ -58,7 +58,7 @@ use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
 //         Patch code for user-defined named cells supports single cells only.
 //         NOTE: this patch only works for BIFF8 as BIFF5-7 use a different
 //         external sheet reference structure
-class Xls extends BaseReader implements IReader
+class Xls extends BaseReader
 {
     // ParseXL definitions
     const XLS_BIFF8 = 0x0600;
diff --git a/src/PhpSpreadsheet/Reader/Xlsx.php b/src/PhpSpreadsheet/Reader/Xlsx.php
index e2e7b052..1e8828fb 100644
--- a/src/PhpSpreadsheet/Reader/Xlsx.php
+++ b/src/PhpSpreadsheet/Reader/Xlsx.php
@@ -28,7 +28,7 @@ use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
 use XMLReader;
 use ZipArchive;
 
-class Xlsx extends BaseReader implements IReader
+class Xlsx extends BaseReader
 {
     /**
      * ReferenceHelper instance.
diff --git a/src/PhpSpreadsheet/Reader/Xml.php b/src/PhpSpreadsheet/Reader/Xml.php
index 18f90728..9b60f27a 100644
--- a/src/PhpSpreadsheet/Reader/Xml.php
+++ b/src/PhpSpreadsheet/Reader/Xml.php
@@ -18,7 +18,7 @@ use PhpOffice\PhpSpreadsheet\Style\Font;
 /**
  * Reader for SpreadsheetML, the XML schema for Microsoft Office Excel 2003.
  */
-class Xml extends BaseReader implements IReader
+class Xml extends BaseReader
 {
     /**
      * Formats.
diff --git a/src/PhpSpreadsheet/Style/Alignment.php b/src/PhpSpreadsheet/Style/Alignment.php
index 9b284a04..61be321e 100644
--- a/src/PhpSpreadsheet/Style/Alignment.php
+++ b/src/PhpSpreadsheet/Style/Alignment.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class Alignment extends Supervisor implements IComparable
+class Alignment extends Supervisor
 {
     // Horizontal alignment styles
     const HORIZONTAL_GENERAL = 'general';
diff --git a/src/PhpSpreadsheet/Style/Border.php b/src/PhpSpreadsheet/Style/Border.php
index e70a25ee..829b8fd0 100644
--- a/src/PhpSpreadsheet/Style/Border.php
+++ b/src/PhpSpreadsheet/Style/Border.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class Border extends Supervisor implements IComparable
+class Border extends Supervisor
 {
     // Border style
     const BORDER_NONE = 'none';
diff --git a/src/PhpSpreadsheet/Style/Borders.php b/src/PhpSpreadsheet/Style/Borders.php
index da1064d6..d4e93661 100644
--- a/src/PhpSpreadsheet/Style/Borders.php
+++ b/src/PhpSpreadsheet/Style/Borders.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class Borders extends Supervisor implements IComparable
+class Borders extends Supervisor
 {
     // Diagonal directions
     const DIAGONAL_NONE = 0;
diff --git a/src/PhpSpreadsheet/Style/Color.php b/src/PhpSpreadsheet/Style/Color.php
index d1c8410d..bb6ed53f 100644
--- a/src/PhpSpreadsheet/Style/Color.php
+++ b/src/PhpSpreadsheet/Style/Color.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class Color extends Supervisor implements IComparable
+class Color extends Supervisor
 {
     // Colors
     const COLOR_BLACK = 'FF000000';
diff --git a/src/PhpSpreadsheet/Style/Fill.php b/src/PhpSpreadsheet/Style/Fill.php
index 0e97d7de..0c2d1b5e 100644
--- a/src/PhpSpreadsheet/Style/Fill.php
+++ b/src/PhpSpreadsheet/Style/Fill.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class Fill extends Supervisor implements IComparable
+class Fill extends Supervisor
 {
     // Fill types
     const FILL_NONE = 'none';
diff --git a/src/PhpSpreadsheet/Style/Font.php b/src/PhpSpreadsheet/Style/Font.php
index 4ad0c991..58499772 100644
--- a/src/PhpSpreadsheet/Style/Font.php
+++ b/src/PhpSpreadsheet/Style/Font.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class Font extends Supervisor implements IComparable
+class Font extends Supervisor
 {
     // Underline types
     const UNDERLINE_NONE = 'none';
diff --git a/src/PhpSpreadsheet/Style/NumberFormat.php b/src/PhpSpreadsheet/Style/NumberFormat.php
index 8147d4d6..a0bfd65e 100644
--- a/src/PhpSpreadsheet/Style/NumberFormat.php
+++ b/src/PhpSpreadsheet/Style/NumberFormat.php
@@ -4,11 +4,10 @@ namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Calculation\MathTrig;
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 use PhpOffice\PhpSpreadsheet\Shared\Date;
 use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 
-class NumberFormat extends Supervisor implements IComparable
+class NumberFormat extends Supervisor
 {
     // Pre-defined formats
     const FORMAT_GENERAL = 'General';
diff --git a/src/PhpSpreadsheet/Style/Protection.php b/src/PhpSpreadsheet/Style/Protection.php
index 1ef3e945..2ae150ed 100644
--- a/src/PhpSpreadsheet/Style/Protection.php
+++ b/src/PhpSpreadsheet/Style/Protection.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class Protection extends Supervisor implements IComparable
+class Protection extends Supervisor
 {
     /** Protection styles */
     const PROTECTION_INHERIT = 'inherit';
diff --git a/src/PhpSpreadsheet/Style/Style.php b/src/PhpSpreadsheet/Style/Style.php
index 11707fbb..99ba8d16 100644
--- a/src/PhpSpreadsheet/Style/Style.php
+++ b/src/PhpSpreadsheet/Style/Style.php
@@ -3,10 +3,9 @@
 namespace PhpOffice\PhpSpreadsheet\Style;
 
 use PhpOffice\PhpSpreadsheet\Cell\Cell;
-use PhpOffice\PhpSpreadsheet\IComparable;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
-class Style extends Supervisor implements IComparable
+class Style extends Supervisor
 {
     /**
      * Font.
diff --git a/src/PhpSpreadsheet/Style/Supervisor.php b/src/PhpSpreadsheet/Style/Supervisor.php
index 1a63ec43..3c7abc60 100644
--- a/src/PhpSpreadsheet/Style/Supervisor.php
+++ b/src/PhpSpreadsheet/Style/Supervisor.php
@@ -2,7 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
-abstract class Supervisor
+use PhpOffice\PhpSpreadsheet\IComparable;
+
+abstract class Supervisor implements IComparable
 {
     /**
      * Supervisor?
diff --git a/src/PhpSpreadsheet/Worksheet/CellIterator.php b/src/PhpSpreadsheet/Worksheet/CellIterator.php
index ce6475a9..ef2ca89d 100644
--- a/src/PhpSpreadsheet/Worksheet/CellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/CellIterator.php
@@ -4,7 +4,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
 
-abstract class CellIterator
+abstract class CellIterator implements \Iterator
 {
     /**
      * Worksheet to iterate.
diff --git a/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php b/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
index 0646e5d4..fdbbfe4c 100644
--- a/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
@@ -5,7 +5,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Cell\Cell;
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
 
-class ColumnCellIterator extends CellIterator implements \Iterator
+class ColumnCellIterator extends CellIterator
 {
     /**
      * Column index.
diff --git a/src/PhpSpreadsheet/Worksheet/Drawing.php b/src/PhpSpreadsheet/Worksheet/Drawing.php
index 12c81041..ebf4b7fa 100644
--- a/src/PhpSpreadsheet/Worksheet/Drawing.php
+++ b/src/PhpSpreadsheet/Worksheet/Drawing.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class Drawing extends BaseDrawing implements IComparable
+class Drawing extends BaseDrawing
 {
     /**
      * Path.
diff --git a/src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php b/src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php
index 18a152e6..b53dde94 100644
--- a/src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php
+++ b/src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php
@@ -3,9 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
-use PhpOffice\PhpSpreadsheet\IComparable;
 
-class HeaderFooterDrawing extends Drawing implements IComparable
+class HeaderFooterDrawing extends Drawing
 {
     /**
      * Path.
diff --git a/src/PhpSpreadsheet/Worksheet/MemoryDrawing.php b/src/PhpSpreadsheet/Worksheet/MemoryDrawing.php
index 7af32444..21cd1310 100644
--- a/src/PhpSpreadsheet/Worksheet/MemoryDrawing.php
+++ b/src/PhpSpreadsheet/Worksheet/MemoryDrawing.php
@@ -2,9 +2,7 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
-use PhpOffice\PhpSpreadsheet\IComparable;
-
-class MemoryDrawing extends BaseDrawing implements IComparable
+class MemoryDrawing extends BaseDrawing
 {
     // Rendering functions
     const RENDERING_DEFAULT = 'imagepng';
diff --git a/src/PhpSpreadsheet/Worksheet/RowCellIterator.php b/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
index a5c05301..06ce0697 100644
--- a/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
@@ -5,7 +5,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Cell\Cell;
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
 
-class RowCellIterator extends CellIterator implements \Iterator
+class RowCellIterator extends CellIterator
 {
     /**
      * Row index.
diff --git a/src/PhpSpreadsheet/Writer/Csv.php b/src/PhpSpreadsheet/Writer/Csv.php
index 34450bf8..a9d3cf55 100644
--- a/src/PhpSpreadsheet/Writer/Csv.php
+++ b/src/PhpSpreadsheet/Writer/Csv.php
@@ -5,12 +5,12 @@ namespace PhpOffice\PhpSpreadsheet\Writer;
 use PhpOffice\PhpSpreadsheet\Calculation\Calculation;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
-class Csv extends BaseWriter implements IWriter
+class Csv extends BaseWriter
 {
     /**
      * PhpSpreadsheet object.
      *
-     * @var PhpSpreadsheet
+     * @var Spreadsheet
      */
     private $spreadsheet;
 
diff --git a/src/PhpSpreadsheet/Writer/Html.php b/src/PhpSpreadsheet/Writer/Html.php
index 33533f2c..69d7db23 100644
--- a/src/PhpSpreadsheet/Writer/Html.php
+++ b/src/PhpSpreadsheet/Writer/Html.php
@@ -24,7 +24,7 @@ use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
 use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
 
-class Html extends BaseWriter implements IWriter
+class Html extends BaseWriter
 {
     /**
      * Spreadsheet object.
diff --git a/src/PhpSpreadsheet/Writer/Ods.php b/src/PhpSpreadsheet/Writer/Ods.php
index 64e163b1..b0babbe1 100644
--- a/src/PhpSpreadsheet/Writer/Ods.php
+++ b/src/PhpSpreadsheet/Writer/Ods.php
@@ -14,7 +14,7 @@ use PhpOffice\PhpSpreadsheet\Writer\Ods\Styles;
 use PhpOffice\PhpSpreadsheet\Writer\Ods\Thumbnails;
 use ZipArchive;
 
-class Ods extends BaseWriter implements IWriter
+class Ods extends BaseWriter
 {
     /**
      * Private writer parts.
@@ -26,7 +26,7 @@ class Ods extends BaseWriter implements IWriter
     /**
      * Private PhpSpreadsheet.
      *
-     * @var PhpSpreadsheet
+     * @var Spreadsheet
      */
     private $spreadSheet;
 
diff --git a/src/PhpSpreadsheet/Writer/Pdf.php b/src/PhpSpreadsheet/Writer/Pdf.php
index 83d7587e..ac94ba37 100644
--- a/src/PhpSpreadsheet/Writer/Pdf.php
+++ b/src/PhpSpreadsheet/Writer/Pdf.php
@@ -8,7 +8,7 @@ use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
 use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
 
-abstract class Pdf extends Html implements IWriter
+abstract class Pdf extends Html
 {
     /**
      * Temporary storage directory.
diff --git a/src/PhpSpreadsheet/Writer/Pdf/Dompdf.php b/src/PhpSpreadsheet/Writer/Pdf/Dompdf.php
index 0872840e..4db6c261 100644
--- a/src/PhpSpreadsheet/Writer/Pdf/Dompdf.php
+++ b/src/PhpSpreadsheet/Writer/Pdf/Dompdf.php
@@ -3,10 +3,9 @@
 namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
 use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
-use PhpOffice\PhpSpreadsheet\Writer\IWriter;
 use PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
-class Dompdf extends Pdf implements IWriter
+class Dompdf extends Pdf
 {
     /**
      * Save Spreadsheet to file.
diff --git a/src/PhpSpreadsheet/Writer/Pdf/Mpdf.php b/src/PhpSpreadsheet/Writer/Pdf/Mpdf.php
index cc829b1f..7a037052 100644
--- a/src/PhpSpreadsheet/Writer/Pdf/Mpdf.php
+++ b/src/PhpSpreadsheet/Writer/Pdf/Mpdf.php
@@ -4,10 +4,9 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
 use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
 use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
-use PhpOffice\PhpSpreadsheet\Writer\IWriter;
 use PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
-class Mpdf extends Pdf implements IWriter
+class Mpdf extends Pdf
 {
     /**
      * Save Spreadsheet to file.
diff --git a/src/PhpSpreadsheet/Writer/Pdf/Tcpdf.php b/src/PhpSpreadsheet/Writer/Pdf/Tcpdf.php
index c4b7aa55..00b6436e 100644
--- a/src/PhpSpreadsheet/Writer/Pdf/Tcpdf.php
+++ b/src/PhpSpreadsheet/Writer/Pdf/Tcpdf.php
@@ -3,10 +3,9 @@
 namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
 use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
-use PhpOffice\PhpSpreadsheet\Writer\IWriter;
 use PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
-class Tcpdf extends Pdf implements IWriter
+class Tcpdf extends Pdf
 {
     /**
      * Save Spreadsheet to file.
diff --git a/src/PhpSpreadsheet/Writer/Xls.php b/src/PhpSpreadsheet/Writer/Xls.php
index 758b04f2..74ce74a9 100644
--- a/src/PhpSpreadsheet/Writer/Xls.php
+++ b/src/PhpSpreadsheet/Writer/Xls.php
@@ -25,7 +25,7 @@ use PhpOffice\PhpSpreadsheet\Worksheet\Drawing;
 use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
 use RuntimeException;
 
-class Xls extends BaseWriter implements IWriter
+class Xls extends BaseWriter
 {
     /**
      * PhpSpreadsheet object.
diff --git a/src/PhpSpreadsheet/Writer/Xlsx.php b/src/PhpSpreadsheet/Writer/Xlsx.php
index 3c0b0977..0982c068 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx.php
@@ -25,7 +25,7 @@ use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Workbook;
 use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Worksheet;
 use ZipArchive;
 
-class Xlsx extends BaseWriter implements IWriter
+class Xlsx extends BaseWriter
 {
     /**
      * Office2003 compatibility.