original_string: public function rulesets($ruleSetFileNames)
      {
          if (!is_array($ruleSetFileNames)) {
              $ruleSetFileNames = [$ruleSetFileNames];
          }
          $this->rulesets = array_unique(array_merge($this->rulesets, $ruleSetFileNames));
  
          return $this;
      }
code: public function rulesets($ruleSetFileNames)
      {
          if (!is_array($ruleSetFileNames)) {
              $ruleSetFileNames = [$ruleSetFileNames];
          }
          $this->rulesets = array_unique(array_merge($this->rulesets, $ruleSetFileNames));
  
          return $this;
      }
code_tokens: public function rulesets ( $ ruleSetFileNames ) { if ( ! is_array ( $ ruleSetFileNames ) ) { $ ruleSetFileNames = [ $ ruleSetFileNames ] ; } $ this -> rulesets = array_unique ( array_merge ( $ this -> rulesets , $ ruleSetFileNames ) ) ; return $ this ; }
docstring: Sets the rule-sets.
  
  @param array|string $ruleSetFileNames
  Array of rule-set filenames or identifiers.
  
  @return $this
docstring_tokens: Sets the rule - sets .