code: def update_counts(self, prior_counts, subtype_counts):
          
          for source, (pos, neg) in prior_counts.items():
              if source not in self.prior_counts:
                  self.prior_counts[source] = [0, 0]
              self.prior_counts[source][0] += pos
              self.prior_counts[source][1] += neg
          for source, subtype_dict in subtype_counts.items():
              if source not in self.subtype_counts:
                  self.subtype_counts[source] = {}
              for subtype, (pos, neg) in subtype_dict.items():
                  if subtype not in self.subtype_counts[source]:
                      self.subtype_counts[source][subtype] = [0, 0]
                  self.subtype_counts[source][subtype][0] += pos
                  self.subtype_counts[source][subtype][1] += neg
          self.update_probs()
docs: Update the internal counts based on given new counts.
  
          Parameters
          ----------
          prior_counts : dict
              A dictionary of counts of the form [pos, neg] for
              each source.
          subtype_counts : dict
              A dictionary of counts of the form [pos, neg] for
              each subtype within a source.