libphonenumber\PhoneNumberUtil::isNationalNumberSuffixOfTheOther PHP Method

    protected function isNationalNumberSuffixOfTheOther(PhoneNumber $firstNumber, PhoneNumber $secondNumber)
    {
        $firstNumberNationalNumber = trim((string) $firstNumber->getNationalNumber());
        $secondNumberNationalNumber = trim((string) $secondNumber->getNationalNumber());
        return $this->stringEndsWithString($firstNumberNationalNumber, $secondNumberNationalNumber) || $this->stringEndsWithString($secondNumberNationalNumber, $firstNumberNationalNumber);
    }