src/share/classes/java/util/function/DoubleBinaryOperator.java

*** 1,7 ****
  /*
!  * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 27,36 ****
--- 27,37 ----
  /**
   * An operation on two {@code double} operands yielding a {@code double} result.
   *
   * @since 1.8
   */
+ @FunctionalInterface
  public interface DoubleBinaryOperator /* extends BinaryOperator<Double> */ {
  //
  //    @Override
  //    public default Double operate(Double left, Double right) { return operateAsDouble((double) left, (double) right); }