def send_message(self, event):
"""Call `matplotlib.backend_managers.ToolManager.message_event`."""
if self.toolmanager.messagelock.locked():
return
from matplotlib.backend_bases import NavigationToolbar2
message = NavigationToolbar2._mouse_event_to_message(event)
if message is None:
message = ' '
self.toolmanager.message_event(message, self)
