For an event 'foo-bar', the corresponding method must be called foo_bar_event().  Therefore, fix the references to zoom_height() in the example.
For an event 'foo-bar', the corresponding method must be called
foo_bar_event().  Therefore, fix the references to zoom_height() in
the example.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator