code: def dequeue(self):
      if self.is_empty():
          raise IndexError("Queue is empty")
      value = self._front.value
      if self._front is self._rear:
          self._front = None
          self._rear = None
      else:
          self._front = self._front.next
      self._size -= 1
      return value
  
imports: from abc import ABCMeta, abstractmethod
label_desc: Use image node_id 4 for calling the LinkedListQueue obj's underlying member method code with example usage: obj.dequeue() and returns: value