+  public function __construct($generate_enclosure = FALSE) {
+    $this->generate_enclosure = $generate_enclosure;
+  }
+
+  public static function epoch_to_gmdate($timestamp)
+  {
+    if (!is_numeric($timestamp) || is_nan($timestamp)) {
+      $timestamp = 0;
+    }
+
+    return gmdate('D, d M Y H:i:s', $timestamp) . ' GMT';
+  }
+
+  public static function str_to_gmdate($date)
+  {
+    $timestamp = strtotime($date);
+    if (FALSE === $timestamp) {
+      $timestamp = 0;
+    }
+
+    return Tweeper::epoch_to_gmdate($timestamp);
+  }
+
+  private static function get_contents($url)
+  {
+    $ch = curl_init($url);
+    curl_setopt_array($ch, array(
+      CURLOPT_HEADER => FALSE,
+      CURLOPT_FOLLOWLOCATION => TRUE,  // follow http redirects to get the real URL
+      CURLOPT_RETURNTRANSFER => TRUE,
+      CURLOPT_SSL_VERIFYHOST => FALSE,
+      CURLOPT_SSL_VERIFYPEER => FALSE,
+      CURLOPT_HTTPHEADER => array('Accept-language: en'),
+      CURLOPT_USERAGENT => Tweeper::$USER_AGENT,
+    ));
+    $contents = curl_exec($ch);
+    curl_close($ch);
+
+    return $contents;
+  }
+
+  private static function get_info($url)
+  {
+    $ch = curl_init($url);
+    curl_setopt_array($ch, array(