* independent stream each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned stream is closed.
   *
   * @throws IOException if an I/O error occurs while opening the stream
   */
  public abstract OutputStream openStream() throws IOException;

  /**
   * Opens a new buffered {@link OutputStream} for writing to this sink. The returned stream is not

          urls.add(new URL("file", null, new File(entry).getAbsolutePath()));
        }
      } catch (MalformedURLException e) {
        AssertionError error = new AssertionError("malformed class path entry: " + entry);
        error.initCause(e);
        throw error;
      }
    }
    return urls.build();
  }

  /**
   * These tests fail in JDK 9 and JDK 10 for an unknown reason. It might be the test; it might be

      absentFeatures = (Feature[]) annotationClass.getMethod("absent").invoke(testerAnnotation);
    } catch (Exception e) {
      throw new IllegalArgumentException("Error extracting features from tester annotation.", e);
    }
    Set<Feature<?>> allPresentFeatures =
        addImpliedFeatures(Helpers.<Feature<?>>copyToSet(presentFeatures));
    Set<Feature<?>> allAbsentFeatures =

         * unavailable. But given how much other reflection we're using, we might as well use it
         * here, too, so that we don't need to also suppress an AndroidApiChecker error.
         */

        Method currentMethod = processHandleClass.getMethod("current");
        Method infoMethod = processHandleClass.getMethod("info");
        Method userMethod = processHandleInfoClass.getMethod("user");

      return true;
    } catch (Error | ClassNotFoundException tolerable) {
      /*
       * We're probably running on Android.
       *
       * A note on exception types:
       *
       * Android API level 10 throws ExceptionInInitializerError the first time and
       * ClassNotFoundException thereafter.
       *
       * Android API level 26 and JVM8 both let our Error propagate directly the first time and

    @JsFunction
    interface ResolveCallbackFn<T extends @Nullable Object> {
      void onInvoke(T value);
    }

    @JsFunction
    interface RejectCallbackFn {
      void onInvoke(Object error);
    }

    void onInvoke(ResolveCallbackFn<T> resolve, RejectCallbackFn reject);
  }

  public Promise(PromiseExecutorCallbackFn<T> executor) {}

  @Override

    static {
      try {
        UNSAFE = getUnsafe();
        Class<?> ak = Cell.class;
        valueOffset = UNSAFE.objectFieldOffset(ak.getDeclaredField("value"));
      } catch (Exception e) {
        throw new Error(e);
      }
    }
  }

  /**
   * ThreadLocal holding a single-slot int array holding hash code. Unlike the JDK8 version of this

 * should use the type safe {@link #putInstance}.
 *
 * <p>Also, if caller suppresses unchecked warnings and passes in an {@code Iterable<String>} for
 * type {@code Iterable<Integer>}, the map won't be able to detect and throw type error.
 *
 * <p>Like any other {@code Map<Class, Object>}, this map may contain entries for primitive types,
 * and a primitive type and its corresponding wrapper type may map to different values.
 *

    class SneakyThrower<T extends Throwable> {
      @SuppressWarnings("unchecked") // intentionally unsafe for test
      void throwIt(Throwable t) throws T {
        throw (T) t;
      }
    }
    new SneakyThrower<Error>().throwIt(t);
  }

  private static class SomeCheckedException extends Exception {}

  private static class SomeUncheckedException extends RuntimeException {}

    class SneakyThrower<T extends Throwable> {
      @SuppressWarnings("unchecked") // intentionally unsafe for test
      void throwIt(Throwable t) throws T {
        throw (T) t;
      }
    }
    new SneakyThrower<Error>().throwIt(t);
  }

  private static class SomeCheckedException extends Exception {}

  private static class SomeUncheckedException extends RuntimeException {}