def get_dynamic_descriptor_children(descriptor, user_id, module_creator=None, usage_key_filter=None):
    """
    Returns the children of the given descriptor, while supporting descriptors with dynamic children.
    """
    module_children = []
    if descriptor.has_dynamic_children():
        module = None
        if descriptor.scope_ids.user_id and user_id == descriptor.scope_ids.user_id:
            # do not rebind the module if it's already bound to a user.
            module = descriptor
        elif module_creator:
            module = module_creator(descriptor)
        if module:
            module_children = module.get_child_descriptors()
    else:
        module_children = descriptor.get_children(usage_key_filter)
    return module_children