function createBigInt(num) {
		if (typeof BigInteger === 'undefined') {
			BigInteger = getBigIntConstructor();
		}
		if (BigInteger === null) {
			throw new Error('BigInt is not supported!');
		}
		return BigInteger(num);
	}
This function creates a bigint value. It allows browsers
that doesn't support BigInt to run the rest of the library
by not directly accessing the BigInt constructor.