original_string: public function setReferrerPolicy($policy = self::SAME_ORIGIN)
      {
          $available = [
              self::NO_REFERRER,
              self::NO_REFERRER_WHEN_DOWNGRADE,
              self::ORIGIN,
              self::ORIGIN_WHEN_CROSS_ORIGIN,
              self::SAME_ORIGIN,
              self::STRICT_ORIGIN,
              self::STRICT_ORIGIN_WHEN_CROSS_ORIGIN,
              self::UNSAFE_URL,
          ];
  
          $this->checkValues($policy, $available);
          $this->headers['referrer-policy'] = $policy;
  
          return $this;
      }
code: public function setReferrerPolicy($policy = self::SAME_ORIGIN)
      {
          $available = [
              self::NO_REFERRER,
              self::NO_REFERRER_WHEN_DOWNGRADE,
              self::ORIGIN,
              self::ORIGIN_WHEN_CROSS_ORIGIN,
              self::SAME_ORIGIN,
              self::STRICT_ORIGIN,
              self::STRICT_ORIGIN_WHEN_CROSS_ORIGIN,
              self::UNSAFE_URL,
          ];
  
          $this->checkValues($policy, $available);
          $this->headers['referrer-policy'] = $policy;
  
          return $this;
      }
code_tokens: public function setReferrerPolicy ( $ policy = self :: SAME_ORIGIN ) { $ available = [ self :: NO_REFERRER , self :: NO_REFERRER_WHEN_DOWNGRADE , self :: ORIGIN , self :: ORIGIN_WHEN_CROSS_ORIGIN , self :: SAME_ORIGIN , self :: STRICT_ORIGIN , self :: STRICT_ORIGIN_WHEN_CROSS_ORIGIN , self :: UNSAFE_URL , ] ; $ this -> checkValues ( $ policy , $ available ) ; $ this -> headers [ 'referrer-policy' ] = $ policy ; return $ this ; }
docstring: Referrer-Policy
  
  @link https://w3c.github.io/webappsec-referrer-policy
  @param string $policy Policy value. Available Value: 'no-referrer', 'no-referrer-when-downgrade', 'origin',
  'origin-when-cross-origin', 'same-origin', 'strict-origin', 'strict-origin-when-cross-origin', 'unsafe-url'
  @return $this
docstring_tokens: Referrer - Policy