started.countDown();
                  try {
                    return method.invoke(delegate, args);
                  } catch (InvocationTargetException e) {
                    throw e.getCause();
                  } finally {
                    awaitUninterruptibly(canReturn);
                    returned.countDown();
                  }
                }
              });

       * exist but throw, so we propagate anything that's thrown, presumably an unchecked Exception
       * or Error.
       */
      throwIfUnchecked(e.getCause());
      throw new AssertionError(e.getCause());
    }
  }

                  started.countDown();
                  try {
                    return method.invoke(delegate, args);
                  } catch (InvocationTargetException e) {
                    throw e.getCause();
                  } finally {
                    awaitUninterruptibly(canReturn);
                    returned.countDown();
                  }
                }
              });

            try (final InputStream is = new BufferedInputStream(responseData.getResponseBody())) {
                out.write(is);
            } catch (final IOException e) {
                if (!(e.getCause() instanceof ClientAbortException)) {
                    throw new FessSystemException("Failed to write a content. configId: " + configId + ", url: " + url, e);
                }
            } finally {

      throw new RuntimeException("Couldn't invoke ThreadManager.currentRequestThreadFactory", e);
    } catch (InvocationTargetException e) {
      // `currentRequestThreadFactory` has no `throws` clause.
      throw sneakyThrow(e.getCause());
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // TODO
  private static boolean isAppEngineWithApiClasses() {
    if (System.getProperty("com.google.appengine.runtime.environment") == null) {

      // requireNonNull is safe because ExampleStackTrace sets a non-null message.
      StringBuilder message = new StringBuilder(requireNonNull(super.getMessage()));
      for (Throwable t = conflictingStackTrace; t != null; t = t.getCause()) {
        message.append(", ").append(t.getMessage());
      }
      return message.toString();
    }
  }

  /**

          }
        }

        // at this point e is either null or expired;
        return lockedGetOrLoad(key, hash, loader);
      } catch (ExecutionException ee) {
        Throwable cause = ee.getCause();
        if (cause instanceof Error) {
          throw new ExecutionError((Error) cause);
        } else if (cause instanceof RuntimeException) {
          throw new UncheckedExecutionException(cause);
        }

          }
        }

        // at this point e is either null or expired;
        return lockedGetOrLoad(key, hash, loader);
      } catch (ExecutionException ee) {
        Throwable cause = ee.getCause();
        if (cause instanceof Error) {
          throw new ExecutionError((Error) cause);
        } else if (cause instanceof RuntimeException) {
          throw new UncheckedExecutionException(cause);
        }