code: public XExtension getByName(String name) {
                  for (XExtension ext : extensionList) {
                          if (ext.getName().equals(name)) {
                                  return ext;
                          }
                  }
                  return null;
          }
docs: Retrieves an extension by its name. If no extension by that name can
  be found, this method returns <code>null</code>.
  
  @param name The name of the requested extension.
  @return The requested extension (may be <code>null</code>, if it
  cannot be found).