code: public final <P> P as(Function<? super Mono<T>, P> transformer) {
  		return transformer.apply(this);
  	}
docs: Transform this {@link Mono} into a target type.
  
  <blockquote><pre>
  {@code mono.as(Flux::from).subscribe() }
  </pre></blockquote>
  
  @param transformer the {@link Function} to immediately map this {@link Mono}
  into a target type
  @param <P> the returned instance type
  
  @return the {@link Mono} transformed to an instance of P
  @see #compose for a bounded conversion to {@link Publisher}