default <O> @NonNull ParserDescriptor<C, O> flatMapSuccess(
            final @NonNull Class<O> mappedType,
            final @NonNull BiFunction<CommandContext<C>, T, CompletableFuture<ArgumentParseResult<O>>> mapper
    ) {
        return parserDescriptor(this.parser().flatMapSuccess(mapper), mappedType);
    }
Create a descriptor for a {@link ArgumentParser#flatMapSuccess(BiFunction) flatMapped} parser.

@param mappedType mapped parser result type
@param mapper     mapper
@param <O>        mapped parser result type
@return mapped parser descriptor
cloud-core/src/main/java/org/incendo/cloud/parser/ParserDescriptor.java