'Add a callback to be invoked on a session periodically.
Args:
callback (callable) :
A callback function to execute periodically
period_milliseconds (int) :
Number of milliseconds between each callback execution.
Returns:
PeriodicCallback :
.. note::
Periodic callbacks only work within the context of a Bokeh server
session. This function will no effect when Bokeh outputs to
standalone HTML or Jupyter notebook cells.'

def add_periodic_callback(self, callback, period_milliseconds):

    from .server.callbacks import PeriodicCallback
    cb = PeriodicCallback(self, None, period_milliseconds)
    return self._add_session_callback(cb, callback, one_shot=False)
