public int getValue() {
        return value;
    }
Parses English-language string {@code id} representing {@link DistanceUnit} object.
If the string cannot be parsed to a valid unit, {@code defaultUnit} will be returned

@param id     string like "km" to parse
@param defaultUnit unit which will be returned if parsing fails
@return DistanceUnit object corresponding to the string, or {@code defaultUnit}
if the string cannot be parsed
main/src/main/java/cgeo/geocaching/location/DistanceUnit.java