Draw a quadrilateral.

def drawQuad(page, quad, color=None, fill=None, dashes=None,
             width=1, roundCap=False, morph=None, overlay=True):
    """Draw a quadrilateral.
    """
    img = page.newShape()
    Q = img.drawQuad(Quad(quad))
    img.finish(color=color, fill=fill, dashes=dashes, width=width,
                   roundCap=roundCap, morph=morph)
    img.commit(overlay)

    return Q