TypeToken<?> token = of(bound);
    if (token.getRawType().isInterface()) {
      return null;
    }
    @SuppressWarnings("unchecked") // only upper bound of T is passed in.
    TypeToken<? super T> superclass = (TypeToken<? super T>) token;
    return superclass;
  }

  /**
   * Returns the generic interfaces that this type directly {@code implements}. This method is

    }
  }

  /**
   * On a concurrent computation that returns null, all threads should get an
   * InvalidCacheLoadException, with the loader only called once. The result should not be cached (a
   * later request should call the loader again).
   */
  private static void testConcurrentLoadingNull(CacheBuilder<Object, Object> builder)
      throws InterruptedException {

    int count = 10;

		}
		if actualErr == nil && !testCase.shouldPass {
			t.Errorf("Test %d: %s: Expected to fail with <ERROR> \"%s\", but passed instead.", i+1, instanceType, testCase.expectedError.Error())
		}
		// Failed as expected, but does it fail for the expected reason.
		if actualErr != nil && !testCase.shouldPass {

    }
  }

  /**
   * On a concurrent computation that returns null, all threads should get an
   * InvalidCacheLoadException, with the loader only called once. The result should not be cached (a
   * later request should call the loader again).
   */
  private static void testConcurrentLoadingNull(CacheBuilder<Object, Object> builder)
      throws InterruptedException {

    int count = 10;

//
// Conventions:
// * We use the prefix TF_ for everything in the API.
// * Objects are always passed around as pointers to opaque structs
//   and these structs are allocated/deallocated via the API.
// * TF_Status holds error information.  It is an object type
//   and therefore is passed around as a pointer to an opaque
//   struct as mentioned above.
// * Every call that has a TF_Status* argument clears it on success

   * the two sets. If you have reason to believe one of your sets will generally be smaller than the
   * other, pass it first. Unfortunately, since this method sets the generic type of the returned
   * set based on the type of the first set passed, this could in rare cases force you to make a
   * cast, for example:
   *
   * <pre>{@code
   * Set<Object> aFewBadObjects = ...
   * Set<String> manyBadStrings = ...
   *

      listOf(
        Header(Header.TARGET_METHOD, "GET"),
        Header(Header.TARGET_SCHEME, "https"),
        Header(Header.TARGET_AUTHORITY, "squareup.com"),
        Header(Header.TARGET_PATH, "/cached"),
      )
    peer.sendFrame().pushPromise(3, 2, expectedRequestHeaders)
    val expectedResponseHeaders =
      listOf(
        Header(Header.RESPONSE_STATUS, "200"),
      )

				t.Errorf("Test %d: %s:  Expected to pass, but failed with: <ERROR> %s", i+1, instanceType, err.Error())
			}
			if err == nil && !testCase.shouldPass {
				t.Errorf("Test %d: %s: Expected to fail with <ERROR> \"%s\", but passed instead", i+1, instanceType, testCase.err.Error())
			}
			// Failed as expected, but does it fail for the expected reason.
			if err != nil && !testCase.shouldPass {

     * concurrently, returning once any connection connects successfully.
     *
     * This implements Happy Eyeballs ([RFC 6555][rfc_6555]), balancing connect latency vs.
     * wasted resources.
     *
     * Defaults to enabled, call with [fastFallback] = false to revert to 4.x behaviour.
     *
     * [rfc_6555]: https://datatracker.ietf.org/doc/html/rfc6555
     */

            argumentMapping[valueArgument] = parameterSymbol
        }
    }

    private fun FirExpression.findSourceKtExpressionForCallArgument(): KtExpression? {
        // For smart-casted expression, refer to the source of the original expression
        // For spread, named, and lambda arguments, the source is the KtValueArgument.