'Register a custom template global, available application wide.  Like
:meth:`Flask.template_global` but for a blueprint.
.. versionadded:: 0.10
:param name: the optional name of the global, otherwise the
function name will be used.'

def app_template_global(self, name=None):

    def decorator(f):
        self.add_app_template_global(f, name=name)
        return f
    return decorator
