code: public function maxChildren($conditionType)
      {
          $factory = $this->factories->has($conditionType) ? $this->getFactory($conditionType) : null;
          if (!$factory instanceof NestablePropertyConditionFactoryInterface) {
              if (null !== $value = $this->fallbackFactory->maxChildren($conditionType)) {
                  return $value;
              }
              return 0;
          }
  
          return $factory->maxChildren();
      }
docs: Get the amount of children this type supports - for unlimited, returns -1.
  
  @param string $conditionType The type name.
  
  @return int