code: public static function getNormalizedParameters(array $data)
      {
          $params = array();
  
          $keys   = array_map('PSX\Oauth\Consumer::urlEncode', array_keys($data));
          $values = array_map('PSX\Oauth\Consumer::urlEncode', array_values($data));
          $data   = array_combine($keys, $values);
  
  
          uksort($data, 'strnatcmp');
  
  
          foreach ($data as $k => $v) {
              if ($k != 'oauth_signature') {
                  $params[] = $k . '=' . $v;
              }
          }
  
          return implode('&', $params);
      }
docs: Returns the parameters that we need to create the basestring
  
  @param array $data
  @return string