Helper for :meth:`Batch.insert` et aliae.

    :type table: str
    :param table: Name of the table to be modified.

    :type columns: list of str
    :param columns: Name of the table columns to be modified.

    :type values: list of lists
    :param values: Values to be modified.

    :rtype: :class:`google.cloud.spanner_v1.proto.mutation_pb2.Mutation.Write`
    :returns: Write protobuf

def _make_write_pb(table, columns, values):
    """Helper for :meth:`Batch.insert` et aliae.

    :type table: str
    :param table: Name of the table to be modified.

    :type columns: list of str
    :param columns: Name of the table columns to be modified.

    :type values: list of lists
    :param values: Values to be modified.

    :rtype: :class:`google.cloud.spanner_v1.proto.mutation_pb2.Mutation.Write`
    :returns: Write protobuf
    """
    return Mutation.Write(
        table=table, columns=columns, values=_make_list_value_pbs(values)
    )