code: public function addChild($child)
      {
          if (!\is_array($child)) {
              throw new \RuntimeException('Error Processing sub filter: ' . var_export($child, true), 1);
          }
  
          switch (strtoupper($child['operation'])) {
              case '=':
              case '>':
              case '<':
                  return $this->getFilterForComparingOperator($child);
  
              case 'IN':
                  return $this->getFilterForInList($child);
  
              case 'LIKE':
                  return $this->getFilterForLike($child);
  
              default:
          }
  
          throw new \RuntimeException('Error processing filter array ' . var_export($child, true), 1);
      }
docs: Add a filter condition child.
  
  @param array $child The child.
  
  @return FilterBuilderSql
  
  @throws \RuntimeException When an invalid filter array has been passed.