code: def OnRemoveReaders(self, removedreaders):
          
          self.mutex.acquire()
          try:
              parentnode = self.root
              for readertoremove in removedreaders:
                  (childReader, cookie) = self.GetFirstChild(parentnode)
                  while childReader.IsOk():
                      if self.GetItemText(childReader) == str(readertoremove):
                          self.Delete(childReader)
                      else:
                          (childReader, cookie) = \
                              self.GetNextChild(parentnode, cookie)
              self.Expand(self.root)
          finally:
              self.mutex.release()
          self.EnsureVisible(self.root)
          self.Repaint()
docs: Called when a reader is removed.
          Removes the reader from the smartcard readers tree.