function apiRequestMultimedia($method, $parameters) {
  if (!is_string($method)) {
    error_log("Method name must be a string\n");
    return false;
  }

  if (!$parameters) {
    $parameters = array();
  } else if (!is_array($parameters)) {
    error_log("Parameters must be an array\n");
    return false;
  }

  foreach ($parameters as $key => &$val) {
    // encoding to JSON array parameters, for example reply_markup
    if (!is_numeric($val) && !is_string($val)) {
      $val = json_encode($val);
    }
  }

  $url = API_URL.$method.'?'.http_build_query($parameters);

  $handle = curl_init($url);
  curl_setopt($handle, CURLOPT_HTTPHEADER, array("Content-Type:multipart/form-data"));
  curl_setopt($handle, CURLOPT_URL, $url);
  curl_setopt($handle, CURLOPT_RETURNTRANSFER, 1);
  curl_setopt($handle, CURLOPT_POSTFIELDS, $parameters);

  return exec_curl_request($handle);
}