original_string: public function useDb($database)
      {
          switch ($this->driver) {
              case 'mysql':
                  $this->query("USE `$database`");
                  $this->dbname = $database;
                  break;
  
              default:
                  throw new \RuntimeException(sprintf('Unsupported switching database for current driver: %s', $this->driver));
          }
          return $this;
      }
code: public function useDb($database)
      {
          switch ($this->driver) {
              case 'mysql':
                  $this->query("USE `$database`");
                  $this->dbname = $database;
                  break;
  
              default:
                  throw new \RuntimeException(sprintf('Unsupported switching database for current driver: %s', $this->driver));
          }
          return $this;
      }
code_tokens: public function useDb ( $ database ) { switch ( $ this -> driver ) { case 'mysql' : $ this -> query ( "USE `$database`" ) ; $ this -> dbname = $ database ; break ; default : throw new \ RuntimeException ( sprintf ( 'Unsupported switching database for current driver: %s' , $ this -> driver ) ) ; } return $ this ; }
docstring: Switch to specified database
  
  @param string $database
  @return $this
docstring_tokens: Switch to specified database