def __call__(self, n=<NUM_LIT:1>, timeout=<NUM_LIT:30>, show_clicks=True):
self.show_clicks = show_clicks<EOL>self.clicks      = []<EOL>self.marks       = []<EOL>BlockingInput.__call__(self,n=n,timeout=timeout)<EOL>return self.clicks<EOL>
Blocking call to retrieve n coordinate pairs through mouse
clicks.