class_docstr: MultiProblem base class.
class_docstr_tok: ["MultiProblem","base","class","."]
code: def generate_data(self, data_dir, tmp_dir, task_id=-1):
      assert len(self.task_list) > 1
      for task in self.task_list:
          task.generate_data(data_dir, tmp_dir, task_id)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_problems
  from tensor2tensor.layers import common_layers
  from tensor2tensor.layers import discretization
  from tensor2tensor.layers import modalities
  from tensor2tensor.utils import metrics
  import tensorflow.compat.v1
  from tensorflow.compat.v1 import estimator
label_desc: Use image node_id 2 for calling the MultiProblem obj's underlying member method code with example usage: obj.generate_data(data_dir, tmp_dir, task_id) without return types