code: protected function createPlaceholder($value, &$params)
      {
          if ($value instanceof ExpressionInterface) {
              return $this->queryBuilder->buildExpression($value, $params);
          }
  
          return $this->queryBuilder->bindParam($value, $params);
      }
docs: Attaches $value to $params array and returns placeholder.
  
  @param mixed $value
  @param array $params passed by reference
  @return string