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();
    }
  }

  /**

synchronized class ExceptionUtils { static final String WRAPPED_MARKER = [wrapped] ; protected static String[] CAUSE_METHOD_NAMES; protected void ExceptionUtils(); public static void addCauseMethodName(String); public static Throwable getCause(Throwable); public static Throwable getCause(Throwable, String[]); public static Throwable getRootCause(Throwable); private static Throwable getCauseUsingWellKno(Throwable); private static Throwable getCauseUsingMethodN(Throwable, String); private static Throwable get...

          }
        }

        // 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);
        }