def follow_markers(self, start=<NUM_LIT:0>, end=<NUM_LIT>, states=None):
if states is not None:<EOL><INDENT>self.skeleton.set_body_states(states)<EOL><DEDENT>for frame_no, frame in enumerate(self.markers):<EOL><INDENT>if frame_no < start:<EOL><INDENT>continue<EOL><DEDENT>if frame_no >= end:<EOL><INDENT>break<EOL><DEDENT>for states in self._step_to_marker_frame(frame_no):<EOL><INDENT>yield states<EOL><DEDENT><DEDENT>
Iterate over a set of marker data, dragging its skeleton along.

        Parameters
        ----------
        start : int, optional
            Start following marker data after this frame. Defaults to 0.
        end : int, optional
            Stop following marker data after this frame. Defaults to the end of
            the marker data.
        states : list of body states, optional
            If given, set the states of the skeleton bodies to these values
            before starting to follow the marker data.