docs: def createEllipse(self, cx, cy, rx, ry, strokewidth=1, stroke='black', fill='none'):
          """
          Creates an ellipse
          @type  cx: string or int
          @param cx:  starting x-coordinate  
          @type  cy: string or int
          @param cy:  starting y-coordinate 
          @type  rx: string or int
          @param rx:  radius in x direction 
          @type  ry: string or int
          @param ry:  radius in y direction
          @type  strokewidth: string or int
          @param strokewidth:  width of the pen used to draw
          @type  stroke: string (either css constants like "black" or numerical values like "#FFFFFF")
          @param stroke:  color with which to draw the outer limits
          @type  fill: string (either css constants like "black" or numerical values like "#FFFFFF")
          @param fill:  color with which to fill the element (default: no filling)
          @return:  an ellipse object
          """
          style_dict = {'fill':fill, 'stroke-width':strokewidth, 'stroke':stroke}
          myStyle = StyleBuilder(style_dict)
          e = Ellipse(cx, cy, rx, ry)
          e.set_style(myStyle.getStyle())
          return e