def authorizations(auth_url, **scopes) ->dict:
    """
    Return all security definitions.
    Contains only one OAuth2 implicit flow definition.

    :param auth_url: Authorization URL.
    :param scopes: All scopes that should be available (scope_name = 'description as a string').
    """
    return {'oauth2': {'scopes': scopes, 'flow': 'implicit',
        'authorizationUrl': auth_url, 'type': 'oauth2'}}
