code: public function setSafe($options)
      {
          if (is_string($options)) {
              $this->safe[] = $options;
              return $this;
          }
  
          if (is_array($options)) {
              foreach ($options as $key => $value) {
                  $this->safe[] = $value;
              }
              return $this;
          }
  
          throw new InvalidArgumentException(
              'This method expects a string or an array argument.'
          );
      }
docs: Sets option names that are considered safe, in order to bypass escaping.
  
  @param mixed A string or array of option names assumed to be safe from
  escaping.
  @throws \InvalidArgumentException If the method argument isn't a string or
  array.
  @return $this