code: def scale(self, sx, sy=None):
          
          if sy is None:
              sy = sx
          cairo.cairo_scale(self._pointer, sx, sy)
          self._check_status()
docs: Modifies the current transformation matrix (CTM)
          by scaling the X and Y user-space axes
          by :obj:`sx` and :obj:`sy` respectively.
          The scaling of the axes takes place after
          any existing transformation of user space.
  
          If :obj:`sy` is omitted, it is the same as :obj:`sx`
          so that scaling preserves aspect ratios.
  
          :param sx: Scale factor in the X direction.
          :param sy: Scale factor in the Y direction.
          :type sx: float
          :type sy: float