code: def children_as_pi(self, squash=False):
          
          probs = self.child_N
          if squash:
              probs = probs ** .98
          sum_probs = np.sum(probs)
          if sum_probs == 0:
              return probs
          return probs / np.sum(probs)
docs: Returns the child visit counts as a probability distribution, pi
          If squash is true, exponentiate the probabilities by a temperature
          slightly larger than unity to encourage diversity in early play and
          hopefully to move away from 3-3s