'Start an event loop.  This is used to start a blocking event
loop so that interactive functions, such as ginput and
waitforbuttonpress, can wait for events.  This should not be
confused with the main GUI event loop, which is always running
and has nothing to do with this.
This function provides default event loop functionality based
on time.sleep that is meant to be used until event loop
functions for each of the GUI backends can be written.  As
such, it throws a deprecated warning.
This call blocks until a callback function triggers
stop_event_loop() or *timeout* is reached.  If *timeout* is
<=0, never timeout.'

def start_event_loop_default(self, timeout=0):

    str = u'Using    default    event    loop    until    function    specific'
    str += u'    to    this    GUI    is    implemented'
    warnings.warn(str, mplDeprecation)
    if (timeout <= 0):
        timeout = np.inf
    timestep = 0.01
    counter = 0
    self._looping = True
    while (self._looping and ((counter * timestep) < timeout)):
        self.flush_events()
        time.sleep(timestep)
        counter += 1
