class_docstr: Basic data structure of topic, contains topic id and
  corresponding probability.
class_docstr_tok: ["Basic","data","structure","of","topic",",","contains","topic","id","and","corresponding","probability","."]
code: def __init__(self, tid, prob):
      self.tid = tid  # topic id
      self.prob = prob
  
imports: import numpy
label_desc: Use image node_id 1 to create a new Topic object from inherited base classes: object with example: obj = Topic(tid, prob)