public static <C, U, V, Z, O> @NonNull Mapper<C, U, V, Z, O> directMapper(
            final Mapper.@NonNull DirectSuccessMapper<C, U, V, Z, O> mapper) {
        return requireNonNull(mapper, "mapper");
    }
Helper function to create a direct success mapper.

@param mapper mapper
@param <C>    command sender type
@param <U>    first component type
@param <V>    second component type
@param <Z>    third component type
@param <O>    output type
@return mapper
cloud-core/src/main/java/org/incendo/cloud/parser/aggregate/AggregateParserTripletBuilder.java