private void drawHole(){
  if (mDrawHole) {
    mDrawCanvas.drawCircle(mContentRect.width() / 2,mContentRect.height() / 2,getDiameter() / 4,mHolePaint);
  }
}

private void drawHole ( ) { if ( mDrawHole ) { mDrawCanvas . drawCircle ( mContentRect . width ( ) / 2 , mContentRect . height ( ) / 2 , getDiameter ( ) / 4 , mHolePaint ) ; } }
draws the hole in the center of the chart
