Method contains

classpath/java/util/LinkedHashMap.java:112–115

(Object o)

    }

    public boolean contains(Object o) {
      return (o instanceof Entry<?,?>)
        && containsKey(((Entry<?,?>)o).getKey());
    }

    public boolean add(Entry<K, V> e) {
      return put(e.getKey(), e.getValue()) != null;