Return True if the argument is a vertex field type, and False otherwise.

def is_vertex_field_type(graphql_type):
    """Return True if the argument is a vertex field type, and False otherwise."""
    # This will need to change if we ever support complex embedded types or edge field types.
    underlying_type = strip_non_null_from_type(graphql_type)
    return isinstance(underlying_type, (GraphQLInterfaceType, GraphQLObjectType, GraphQLUnionType))