override fun putValue(
    s: String,
    o: Any,
  ) {
    delegate!!.putValue(s, o)
  }

  override fun getValue(s: String): Any = delegate!!.getValue(s)

  override fun removeValue(s: String) {
    delegate!!.removeValue(s)
  }

  override fun getValueNames(): Array<String> = delegate!!.valueNames

  @Throws(SSLPeerUnverifiedException::class)

  override fun getSessionContext(): SSLSessionContext = throw UnsupportedOperationException()

  override fun putValue(
    s: String,
    obj: Any,
  ): Unit = throw UnsupportedOperationException()

  override fun removeValue(s: String): Unit = throw UnsupportedOperationException()

  override fun getValue(s: String): Any = throw UnsupportedOperationException()

  override fun getValueNames(): Array<String> = throw UnsupportedOperationException()

    Object removedValue;

    if (previousValue == null || previousValue == PRED) {
      removedValue = null;
    } else if (previousValue instanceof PredAndSucc) {
      adjacentNodeValues.put((N) node, PRED);
      removedValue = ((PredAndSucc) previousValue).successorValue;
    } else { // successor
      adjacentNodeValues.remove(node);
      removedValue = previousValue;
    }