reactor-core/src/main/java/reactor/core/publisher/ParallelFlux.java
public final ParallelFlux<T> filter(Predicate<? super T> predicate) {
		Objects.requireNonNull(predicate, "predicate");
		return onAssembly(new ParallelFilter<>(this, predicate));
	}
public final ParallelFlux<T> filter(Predicate<? super T> predicate) {
		Objects.requireNonNull(predicate, "predicate");
		return onAssembly(new ParallelFilter<>(this, predicate));
	}
Filters the source values on each 'rail'.
<p>
Note that the same predicate may be called from multiple threads concurrently.

@param predicate the function returning true to keep a value or false to drop a
value

@return the new {@link ParallelFlux} instance