def validate_positional_constraint(positional_constraint):
    """
    Validate positional constraint for ByteMatchStatement
    Property: ByteMatchStatement.PositionalConstraint
    """

    VALID_POSITIONAL_CONSTRAINTS = (
        "CONTAINS",
        "CONTAINS_WORD",
        "ENDS_WITH",
        "EXACTLY",
        "STARTS_WITH",
    )

    if positional_constraint not in VALID_POSITIONAL_CONSTRAINTS:
        raise ValueError(
            "ByteMatchStatement PositionalConstraint must be one of: %s"
            % ", ".join(VALID_POSITIONAL_CONSTRAINTS)  # NOQA
        )
    return positional_constraint