def _new_value_pb(entity_pb, name):
    """Add (by name) a new ``Value`` protobuf to an entity protobuf.

    :type entity_pb: :class:`gcloud.datastore._generated.entity_pb2.Entity`
    :param entity_pb: An entity protobuf to add a new property to.

    :type name: string
    :param name: The name of the new property.

    :rtype: :class:`gcloud.datastore._generated.entity_pb2.Value`
    :returns: The new ``Value`` protobuf that was added to the entity.
    """
    property_pb = entity_pb.property.add()
    property_pb.name = name
    return property_pb.value