code: public static <T extends ClassLoader> ElementMatcher.Junction<T> isExtensionClassLoader() {
          ClassLoader classLoader = ClassLoader.getSystemClassLoader().getParent();
          return classLoader == null // Check if VM supports the extension class loader.
                  ? ElementMatchers.<T>none()
                  : new EqualityMatcher<T>(classLoader);
      }
docs: Matches exactly the extension {@link java.lang.ClassLoader}. The returned matcher is a synonym to
  a matcher matching {@code ClassLoader.gerSystemClassLoader().getParent()}.
  
  @param <T> The type of the matched object.
  @return A matcher that only matches the extension class loader.