code: public function run($query, array $arguments = array())
    {
      $stmt = $this->prepare($query);
      $stmt->execute($arguments);
      return $stmt;
    }
docs: PDO::prepare()::execute() chaining wrapper.
  
  @param string SQL query with placeholders.
  @param array substitution variables.
  @return PDOStatement
  
  @see PDO::prepare()
  @see PDOStatement::execute()