code: protected function setMaxChildren($maxChildren)
      {
          if (!$this->isNestedType()) {
              throw new \LogicException('Filter setting ' . $this->typeClass . ' can not handle children.');
          }
  
          $this->maxChildren = $maxChildren;
  
          return $this;
      }
docs: Set the maximum amount of allowed children (only valid when isNestedType() == true).
  
  @param int|null $maxChildren The amount of children.
  
  @return AbstractFilterSettingTypeFactory
  
  @throws \LogicException When the filter setting can not handle children (is not nested type).