code: def createRect(self, x, y, width, height, rx=None, ry=None, strokewidth=1, stroke='black', fill='none'):
          
          style_dict = {'fill':fill, 'stroke-width':strokewidth, 'stroke':stroke}
          myStyle = StyleBuilder(style_dict)
          r = Rect(x, y, width, height, rx, ry)
          r.set_style(myStyle.getStyle())
          return r
docs: Creates a Rectangle
          @type  x: string or int
          @param x:  starting x-coordinate  
          @type  y: string or int
          @param y:  starting y-coordinate 
          @type  width: string or int
          @param width:  width of the rectangle  
          @type  height: string or int
          @param height:  height of the rectangle 
          @type  rx: string or int
          @param rx:  For rounded rectangles, the x-axis radius of the ellipse used to round off the corners of the rectangle. 
          @type  ry: string or int
          @param ry:  For rounded rectangles, the y-axis radius of the ellipse used to round off the corners of the rectangle.
          @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:  a rect object