code: def __getitem__(self, node_id):
      return self.nodes[node_id]
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  from turicreate.util import _raise_error_if_not_of_type
  from turicreate.toolkits._internal_utils import _numeric_param_check_range
  import sys
label_desc: Use image node_id 10 for calling the DecisionTree obj's underlying member method code with example usage: obj.__getitem__(node_id) and returns: self