Check if the given objecttype has Node as an interface

def is_node(objecttype):
    """
    Check if the given objecttype has Node as an interface
    """
    if not isclass(objecttype):
        return False

    if not issubclass(objecttype, ObjectType):
        return False

    for i in objecttype._meta.interfaces:
        if issubclass(i, Node):
            return True

    return False