code: public function verify($baseString, $consumerSecret, $tokenSecret = '', $signature)
      {
          $lft = Consumer::urlDecode($signature);
          $rgt = Consumer::urlDecode($this->build($baseString, $consumerSecret, $tokenSecret));
  
          return strcasecmp($lft, $rgt) == 0;
      }
docs: Compares whether the $signature is valid by creating a new signature
  and comparing them with $signature
  
  @param string $baseString
  @param string $consumerSecret
  @param string $tokenSecret
  @param string $signature
  @return boolean