Java Utililty Methods BigInteger Power

BigInteger pow(BigInteger base, BigInteger exponent)
pow

BigInteger result = BigInteger.ONE;
while (exponent.signum() > 0) {
 if (exponent.testBit(0))
 result = result.multiply(base);
 base = base.multiply(base);
 exponent = exponent.shiftRight(1);
return result;
...

BigInteger Power(BigInteger base, int exp)
Power

BigInteger powerResultat = new BigInteger("1");
if (exp == 1) {
 return base;
if (exp == 0) {
 return powerResultat;
for (int i = 0; i < exp; ++i) {
...

BigInteger powerToEnergy(BigInteger power, Integer ptuDuration)
Transforms a power (Watt) of a PTU to an energy (Watt hour).

BigDecimal hoursPerPtu = new BigDecimal(Hours.ONE.toStandardMinutes().getMinutes())
 .divide(new BigDecimal(ptuDuration), DECIMAL_PRECISION, RoundingMode.HALF_UP);
return new BigDecimal(power).divide(hoursPerPtu, DECIMAL_PRECISION, RoundingMode.HALF_UP).toBigInteger();