Method keySet

classpath/java/util/Collections.java:309–311

()

      synchronized (lock) { return map.isEmpty(); }
    }
    public Set<K> keySet() {
      synchronized (lock) { return new SynchronizedSet<K>(lock, map.keySet()); }
    }
    public V put(K key, V value) {
      synchronized (lock) { return map.put(key, value); }
    }