def start_gesture(self, pos):
return PendingGestureAction(self, pos)<EOL>
Start a gesture action. This method will return a :py:class:`PendingGestureAction
<poco.gesture.PendingGestureAction>` object which is able to generate decomposed gesture steps. You can invoke
``.to`` and ``.hold`` any times in a chain. See the following example.

Examples:
    ::

        poco = Poco(...)

        # move from screen center to (0.6w, 0.6h) and hold for 1 second
        # then return back to center
        poco.start_gesture([0.5, 0.5]).to([0.6, 0.6]).hold(1).to([0.5, 0.5]).up()

Args:
    pos: starting coordinate of normalized coordinate system

Returns:
    :py:class:`PendingGestureAction <poco.gesture.PendingGestureAction>`: an object for building serialized
    gesture action.