'Simulates a mouse down event on an image.
Key attributes for images are `id`, `src` and `alt`. See
`introduction` for details about locating elements.'

@keyword
def mouse_down_on_image(self, locator):

    element = self.find_element(locator, tag='image')
    action = ActionChains(self.browser)
    action.click_and_hold(element).perform()
