public static <C, U, V, Z> Mapper<C, U, V, Z, Triplet<U, V, Z>> defaultMapper() {
        return (ctx, u, v, z) -> ArgumentParseResult.successFuture(Triplet.of(u, v, z));
    }
Creates the default mapper that simply returns a {@link Triplet} of the three input values.

@param <C> the command sender type
@param <U> the first type
@param <V> the second type
@param <Z> the third type
@return a default mapper that returns a {@link Triplet} of the three input values
cloud-core/src/main/java/org/incendo/cloud/parser/aggregate/AggregateParserTripletBuilder.java