public static double ConvertUnit(IUnit sourceUnit, IUnit destinationUnit, double valueToConvert)
{
// check if they are the same type
if (sourceUnit == destinationUnit) return valueToConvert;
// if we are converting zero, it's zero
if (valueToConvert == 0) return 0;
// convert sourceUnits to base
var baseValue = sourceUnit.ConvertToBaseUnit(valueToConvert);
// convert base to destination
var destination = destinationUnit.ConvertFromBaseUnit(baseValue);
return destination;
}