guava/src/com/google/common/collect/FluentIterable.java
public final FluentIterable<E> filter(Predicate<? super E> predicate) {
    return from(Iterables.filter(getDelegate(), predicate));
  }
public final FluentIterable<E> filter(Predicate<? super E> predicate) {
    return from(Iterables.filter(getDelegate(), predicate));
  }
Returns the elements from this fluent iterable that satisfy a predicate. The resulting fluent
iterable's iterator does not support {@code remove()}.

<p><b>{@code Stream} equivalent:</b> {@link Stream#filter} (same).