code: def get_prediction_score(self, node_id):
          
          _raise_error_if_not_of_type(node_id, [int,long], "node_id")
          _numeric_param_check_range("node_id", node_id, 0, self.num_nodes - 1)
          node = self.nodes[node_id]
          return None if node.is_leaf is False else node.value
docs: Return the prediction score (if leaf node) or None if its an
          intermediate node.
  
          Parameters
          ----------
          node_id: id of the node to get the prediction value.
  
          Returns
          -------
          float or None: returns float value of prediction if leaf node and None
          if not.
  
          Examples
          --------
          .. sourcecode:: python
  
              >>> tree.get_prediction_score(120)  # Leaf node
              0.251092
  
              >>> tree.get_prediction_score(120)  # Not a leaf node
              None