Holds down the left mouse button on the source element,
           then moves to the target element and releases the mouse button.

        :Args:
         - source: The element to mouse down.
         - target: The element to mouse up.

def drag_and_drop(self, source, target):
        """
        Holds down the left mouse button on the source element,
           then moves to the target element and releases the mouse button.

        :Args:
         - source: The element to mouse down.
         - target: The element to mouse up.
        """
        self.click_and_hold(source)
        self.release(target)
        return self