Method filter

output/java_guava/1.4.16/Collections2.java:90–97

(Collection<E> unfiltered, Predicate<? super E> predicate)

  public static <E> Collection<E> filter(Collection<E> unfiltered, Predicate<? super E> predicate) {
    if (unfiltered instanceof FilteredCollection) {
      // Support clear(), removeAll(), and retainAll() when filtering a filtered
      // collection.
      return ((FilteredCollection<E>) unfiltered).createCombined(predicate);
    }
    return new FilteredCollection<E>(checkNotNull(unfiltered), checkNotNull(predicate));
  }

  /**
   * Delegates to {@link Collection#contains}. Returns {@code false} if the