Remove unused Polygon class

@@ -58,7 +58,6 @@ part 'src/page.dart';
 part 'src/page_format.dart';
 part 'src/page_list.dart';
 part 'src/point.dart';
-part 'src/polygon.dart';
 part 'src/rect.dart';
 part 'src/signature.dart';
 part 'src/stream.dart';

@@ -180,15 +180,6 @@ class PdfGraphics {
     lineTo(x2, y2);
   }
 
-  /// Draws a polygon, linking the first and last coordinates.
-  ///
-  /// @param xp Array of x coordinates
-  /// @param yp Array of y coordinates
-  /// @param np number of points in polygon
-  void drawPolygon(PdfPolygon p) {
-    _polygon(p.points);
-  }
-
   void drawEllipse(double x, double y, double r1, double r2) {
     moveTo(x, y - r2);
     curveTo(x + _m4 * r1, y - r2, x + r1, y - _m4 * r2, x + r1, y);
@@ -685,22 +676,6 @@ class PdfGraphics {
     }
   }
 
-  /// This is used to add a polygon to the current path.
-  /// Used by drawPolygon()
-  ///
-  /// @param p Array of coordinates
-  /// @see #drawPolygon
-  /// @see #drawPolyline
-  /// @see #fillPolygon
-  void _polygon(List<PdfPoint> p) {
-    // newPath() not needed here as moveto does it ;-)
-    moveTo(p[0].x, p[0].y);
-
-    for (int i = 1; i < p.length; i++) {
-      lineTo(p[i].x, p[i].y);
-    }
-  }
-
   void setLineCap(PdfLineCap cap) {
     buf.putString('${cap.index} J\n');
   }

-/*
- * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-part of pdf;
-
-class PdfPolygon {
-  PdfPolygon(this.points);
-
-  List<PdfPoint> points;
-
-  PdfRect getBounds() {
-    // TODO(me): Implement properly
-    return const PdfRect(0, 0, 0, 0);
-  }
-}