class_docstr: Stack class
class_docstr_tok: ["Stack","class"]
docstr: pop an item from the stack
  @return : poped item
  @rtype: mixed
docstr_tok: ["pop","an","item","from","the","stack","@","return",":","poped","item","@","rtype",":","mixed"]
code: def pop(self):
      """
      pop an item from the stack
      @return : poped item
      @rtype: mixed
      """
      if not self.is_empty():
          return self.items.pop()
      else:
          return None
  
label_desc: Use image node_id 3 for calling the Stack obj's underlying member method code with example usage: obj.pop() and returns: self, None