code: def frames(self):
          
          color_im = self._read_color_image()
          depth_im = self._read_depth_image()
          return color_im, depth_im, None
docs: Retrieve a new frame from the Kinect and convert it to a ColorImage,
          a DepthImage, and an IrImage.
  
          Returns
          -------
          :obj:`tuple` of :obj:`ColorImage`, :obj:`DepthImage`, :obj:`IrImage`, :obj:`numpy.ndarray`
              The ColorImage, DepthImage, and IrImage of the current frame.
  
          Raises
          ------
          RuntimeError
              If the Kinect stream is not running.