The ConversionRule struct represents a unit conversion rule from
base unit to second unit within the specified family. Note that in UnitConvertor
class each family can be represented with the single base unit. In other words you
can't have two unit conversion rules with the same family but different base units
The ConversionRule struct represents a unit conversion rule from base unit to second unit within the specified family. Note that in UnitConvertor class each family can be represented with the single base unit. In other words you can't have two unit conversion rules with the same family but different base units