docs: void addImplementedInterface(final String interfaceName, final Map<String, ClassInfo> classNameToClassInfo) {
          final ClassInfo interfaceClassInfo = getOrCreateClassInfo(interfaceName,
                  /* classModifiers = */ Modifier.INTERFACE, classNameToClassInfo);
          interfaceClassInfo.isInterface = true;
          interfaceClassInfo.modifiers |= Modifier.INTERFACE;
          this.addRelatedClass(RelType.IMPLEMENTED_INTERFACES, interfaceClassInfo);
          interfaceClassInfo.addRelatedClass(RelType.CLASSES_IMPLEMENTING, this);
      }