operator - method
Subtracts another power from this power.
The other
power is converted to the unit of this power before subtraction.
The result is a new Power instance with the difference, expressed in the
unit of this power (the left-hand operand).
Implementation
Power operator -(Power other) {
final otherValueInThisUnit = other.getValue(unit);
return Power(value - otherValueInThisUnit, unit);
}