original_string: public function quoteIdentifier( $identifier )
      {
          if ( sizeof( $this->identifierQuoteChars ) === 2 )
          {
              $identifier = 
                  $this->identifierQuoteChars["start"]
                  . str_replace( 
                      $this->identifierQuoteChars["end"],
                      $this->identifierQuoteChars["end"].$this->identifierQuoteChars["end"],
                      $identifier
                    )
                  . $this->identifierQuoteChars["end"];
          }
          return $identifier;
      }
code: public function quoteIdentifier( $identifier )
      {
          if ( sizeof( $this->identifierQuoteChars ) === 2 )
          {
              $identifier = 
                  $this->identifierQuoteChars["start"]
                  . str_replace( 
                      $this->identifierQuoteChars["end"],
                      $this->identifierQuoteChars["end"].$this->identifierQuoteChars["end"],
                      $identifier
                    )
                  . $this->identifierQuoteChars["end"];
          }
          return $identifier;
      }
code_tokens: public function quoteIdentifier ( $ identifier ) { if ( sizeof ( $ this -> identifierQuoteChars ) === 2 ) { $ identifier = $ this -> identifierQuoteChars [ "start" ] . str_replace ( $ this -> identifierQuoteChars [ "end" ] , $ this -> identifierQuoteChars [ "end" ] . $ this -> identifierQuoteChars [ "end" ] , $ identifier ) . $ this -> identifierQuoteChars [ "end" ] ; } return $ identifier ; }
docstring: Returns the quoted version of an identifier to be used in an SQL query.
  This method takes a given identifier and quotes it, so it can safely be
  used in SQL queries.
  
  @param string $identifier The identifier to quote.
  @return string The quoted identifier.
docstring_tokens: Returns the quoted version of an identifier to be used in an SQL query . This method takes a given identifier and quotes it so it can safely be used in SQL queries .