/// <summary>
 /// Initializes a new instance of the <see cref="GraphMouseEventArgs"/>
 /// class by copying the values of the given instance of the same class,
 /// and offsets the new instance's <see cref="Pos"/> by the given
 /// values <paramref name="dx"/> and <paramref name="dy"/>.
 /// </summary>
 /// <param name="e">The <see cref="GraphMouseEventArgs"/> instance
 /// whose values are cloned into this <see cref="GraphMouseEventArgs"/>
 /// instance.</param>
 /// <param name="dx">The horizontal offset to add to
 /// <paramref name="e"/>'s <see cref="X"/> value to get this instance's
 /// <see cref="X"/> value. </param>
 /// <param name="dy">The vertical offset to add to
 /// <paramref name="e"/>'s <see cref="Y"/> value to get this instance's
 /// <see cref="Y"/> value. </param>
 public GraphMouseEventArgs(GraphMouseEventArgs e, float dx, float dy)
 {
     this.Handled = e.Handled;
     this.mButton = e.mButton;
     this.mClicks = e.mClicks;
     this.mSceneX = e.mSceneX;
     this.mSceneY = e.mSceneY;
     this.mX      = e.X + dx;
     this.mY      = e.Y + dy;
     this.mDelta  = e.mDelta;
 }
 /// <summary>
 /// Initializes a new instance of the <see cref="GraphMouseEventArgs"/>
 /// class by copying the values of the given instance of the same class.
 /// </summary>
 /// <param name="e">The <see cref="GraphMouseEventArgs"/> instance
 /// whose values are cloned into this <see cref="GraphMouseEventArgs"/>
 /// instance.</param>
 public GraphMouseEventArgs(GraphMouseEventArgs e) : this(e, 0, 0)
 {
 }