code: @Deprecated
      public static <PE extends ExtensionElement> PE packetExtensionfromCollection(
              Collection<ExtensionElement> collection, String element,
              String namespace) {
          return extensionElementFrom(collection, element, namespace);
      }
docs: Get a extension element from a collection.
  @param collection
  @param element
  @param namespace
  @param <PE>
  @return the extension element
  @deprecated use {@link #extensionElementFrom(Collection, String, String)} instead.