def make_type_entity_id(type_id=None, entity_id=None):
    """
    Assemble a type_id and entity_id and return a composite identifier.

    If the entity Id is blank, ignore the supplied type id

    >>> make_type_entity_id(type_id="type_id", entity_id="entity_id") == "type_id/entity_id"
    True
    >>> make_type_entity_id(type_id="type_id", entity_id="") == ""
    True
    """
    assert type_id is not None,   "make_type_entity_id: no type id (%s, %s)"%(type_id, entity_id)
    assert entity_id is not None, "make_type_entity_id: no entity id (%s, %s)"%(type_id, entity_id)
    if entity_id != "":
        return type_id + "/" + entity_id
    return ""