public static <T> ToShort<T> shortPlusShort(ToShort<T> first, ToShort<T> second) {
        class ShortPlusShort extends AbstractPlus<T, ToShort<T>, ToShort<T>> implements ToShort<T> {
            private ShortPlusShort(ToShort<T> first, ToShort<T> second) {
                super(first, second);
            }

            @Override
            public short applyAsShort(T object) {
                return (short) (firstInner.applyAsShort(object)
                    + secondInner.applyAsShort(object));
            }
        }

        return new ShortPlusShort(first, second);
    }
Creates and returns an expression that takes the result of the two
expressions and add them together.

@param first   the first input expression
@param second  the second input expression
@param <T>     the input type
@return        the new expression
runtime-parent/runtime-compute/src/main/java/com/speedment/runtime/compute/internal/expression/PlusUtil.java