original_string: public function setTagPrefix($prefix)
      {
          if(!is_string($prefix) && $prefix !== null)
          {
              throw new HTMLTagException("The tag prefix must be a string or null.");
          }
  
          $this->tag_prefix_previous = $this->getTagPrefix();
          $this->tag_prefix = $prefix;
  
          return $this;
  
      }
code: public function setTagPrefix($prefix)
      {
          if(!is_string($prefix) && $prefix !== null)
          {
              throw new HTMLTagException("The tag prefix must be a string or null.");
          }
  
          $this->tag_prefix_previous = $this->getTagPrefix();
          $this->tag_prefix = $prefix;
  
          return $this;
  
      }
code_tokens: public function setTagPrefix ( $ prefix ) { if ( ! is_string ( $ prefix ) && $ prefix !== null ) { throw new HTMLTagException ( "The tag prefix must be a string or null." ) ; } $ this -> tag_prefix_previous = $ this -> getTagPrefix ( ) ; $ this -> tag_prefix = $ prefix ; return $ this ; }
docstring: Sets the string that should precede a tag
  @param   string|null $prefix
  @return  HTMLTag
  @throws  HTMLTagException
docstring_tokens: Sets the string that should precede a tag