code: def element_height_should_be(self, locator, expected):
  		
  
  		self._info("Verifying element '%s' height is '%s'" % (locator, expected))
  		self._check_element_size(locator, 'height', expected)
docs: Verifies the element identified by `locator` has the expected
  		height. Expected height should be in pixels.
  
  		| *Argument* | *Description* | *Example* |
  		| locator | Selenium 2 element locator | id=my_id |
  		| expected | expected height | 600 |