code: public function getAuthorizationHeader(Url $url, $consumerKey, $consumerSecret, $token, $tokenSecret, $method = 'HMAC-SHA1', $requestMethod = 'GET', array $post = array())
      {
          $values = array(
              'oauth_consumer_key'     => $consumerKey,
              'oauth_token'            => $token,
              'oauth_signature_method' => $method,
              'oauth_timestamp'        => self::getTimestamp(),
              'oauth_nonce'            => self::getNonce(),
              'oauth_version'          => self::getVersion(),
          );
  
          // build the base string
          $params = array_merge($values, $url->getParameters());
  
          if ($requestMethod == 'POST' && !empty($post)) {
              $params = array_merge($params, $post);
          }
  
          $baseString = self::buildBasestring($requestMethod, $url, $params);
  
          // get the signature object
          $signature = self::getSignature($method);
  
          // generate the signature
          $values['oauth_signature'] = $signature->build($baseString, $consumerSecret, $tokenSecret);
  
          // build request
          $authorizationHeader = 'OAuth realm="psx", ' . self::buildAuthString($values);
  
          return $authorizationHeader;
      }
docs: If you have established a token and token secret you can use this method
  to get the authorization header. You can add the header to an http
  request to make an valid oauth request i.e.
  <code>
  $header = array(
  'Authorization: ' . $oauth->getAuthorizationHeader(...),
  );
  </code>
  
  @param \PSX\Uri\Url $url
  @param string $consumerKey
  @param string $consumerSecret
  @param string $token
  @param string $tokenSecret
  @param string $method
  @param string $requestMethod
  @param array $post
  @return string