code: public static <K, V> Multimap<K, V> filterEntries(
        Multimap<K, V> unfiltered, Predicate<? super Entry<K, V>> entryPredicate) {
      checkNotNull(entryPredicate);
      if (unfiltered instanceof SetMultimap) {
        return filterEntries((SetMultimap<K, V>) unfiltered, entryPredicate);
      }
      return (unfiltered instanceof FilteredMultimap)
          ? filterFiltered((FilteredMultimap<K, V>) unfiltered, entryPredicate)
          : new FilteredEntryMultimap<K, V>(checkNotNull(unfiltered), entryPredicate);
    }
docs: Returns a multimap containing the mappings in {@code unfiltered} that satisfy a predicate. The
  returned multimap is a live view of {@code unfiltered}; changes to one affect the other.
  
  <p>The resulting multimap's views have iterators that don't support {@code remove()}, but all
  other methods are supported by the multimap and its views. When adding a key/value pair that
  doesn't satisfy the predicate, multimap's {@code put()}, {@code putAll()}, and {@code
  replaceValues()} methods throw an {@link IllegalArgumentException}.
  
  <p>When methods such as {@code removeAll()} and {@code clear()} are called on the filtered
  multimap or its views, only mappings whose keys satisfy the filter will be removed from the
  underlying multimap.
  
  <p>The returned multimap isn't threadsafe or serializable, even if {@code unfiltered} is.
  
  <p>Many of the filtered multimap's methods, such as {@code size()}, iterate across every
  key/value mapping in the underlying multimap and determine which satisfy the filter. When a
  live view is <i>not</i> needed, it may be faster to copy the filtered multimap and use the
  copy.
  
  <p><b>Warning:</b> {@code entryPredicate} must be <i>consistent with equals</i>, as documented
  at {@link Predicate#apply}.
  
  @since 11.0