cdm/src/main/java/ucar/nc2/units/SimpleUnit.java
static protected Unit makeUnit(String name) throws UnitException {
    UnitFormat format = UnitFormatManager.instance();
    return format.parse(name);
  }
static protected Unit makeUnit(String name) throws UnitException {
    UnitFormat format = UnitFormatManager.instance();
    return format.parse(name);
  }
need subclass access