def _get_empty(value, empty_value):
    """Check if a protobuf field is "empty".

    :type value: object
    :param value: A basic field from a protobuf.

    :type empty_value: object
    :param empty_value: The "empty" value for the same type as
                        ``value``.
    """
    if value == empty_value:
        return None
    else:
        return value