def key_down(self,locator,keySequence):
self.do_command("<STR_LIT>", [locator,keySequence,])<EOL>
Simulates a user pressing a key (without releasing it yet).

'locator' is an element locator
'keySequence' is Either be a string("\" followed by the numeric keycode  of the key to be pressed, normally the ASCII value of that key), or a single  character. For example: "w", "\119".