reactor-core/src/main/java/reactor/core/publisher/Mono.java
public final <R> Mono<R> map(Function<? super T, ? extends R> mapper) {
		if (this instanceof Fuseable) {
			return onAssembly(new MonoMapFuseable<>(this, mapper));
		}
		return onAssembly(new MonoMap<>(this, mapper));
	}
public final <R> Mono<R> map(Function<? super T, ? extends R> mapper) {
		if (this instanceof Fuseable) {
			return onAssembly(new MonoMapFuseable<>(this, mapper));
		}
		return onAssembly(new MonoMap<>(this, mapper));
	}
Transform the item emitted by this {@link Mono} by applying a synchronous function to it.

<p>
<img class="marble" src="doc-files/marbles/mapForMono.svg" alt="">

@param mapper the synchronous transforming {@link Function}
@param <R> the transformed type

@return a new {@link Mono}