udunits/src/main/java/ucar/units/OffsetUnit.java
@Override
    protected Unit myDivideInto(final Unit that) throws OperationException {
        return that instanceof OffsetUnit
                ? getUnit().divideInto(((OffsetUnit) that).getUnit())
                : getUnit().divideInto(that);
    }
@Override
    protected Unit myDivideInto(final Unit that) throws OperationException {
        return that instanceof OffsetUnit
                ? getUnit().divideInto(((OffsetUnit) that).getUnit())
                : getUnit().divideInto(that);
    }
Divide this unit into another unit.

@param that
The unit to divide this unit into.
@return The quotient of <code>that</code> unit and this unit. The offset
of this unit will be ignored; thus, for example
"celsius.myDivideInto(day)" is equivalent to
"kelvin.myDivideInto(day)".
@throws OperationException
Can't divide these units.