code: def node_impurity(self):
      gini = 0.0
      for k in range(self.n_outputs):
          sq_count = 0.0
          for c in range(int(self.n_classes[k])):
              count_k = self.sum_total[k, c]
              sq_count += count_k * count_k
          gini += 1.0 - sq_count / (
              self.weighted_n_node_samples
              * self.weighted_n_node_samples
          )
      return gini / self.n_outputs
  
imports: from abc import ABC, abstractmethod
  import ivy
label_desc: Use image node_id 1 for calling the Gini obj's underlying member method code with example usage: obj.node_impurity() and returns: unknown