public static <T> ToByte<T> sign(ToInt<T> expression) {
        return SignUtil.signInt(expression);
    }
Creates and returns an expression that returns {@code 1} if the result of
the input expression is positive, {@code -1} if the result of the input
expression is negative and {@code 0} if the result of the input
expression is {@code 0}.

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