code: def __call__(self):
      inputs = [self.dtrain]
      if self.evals is not None:
          inputs.extend(e[0] for e in self.evals)
      return self.new_tileable(inputs)
  
imports: import itertools
  import logging
  import pickle
  from collections import OrderedDict, defaultdict
  import numpy
  from ....None import opcodes
  from ....core import OutputType
  from ....core.context import get_context
  from ....core.operand import MergeDictOperand
  from ....serialization.serializables import FieldTypes, DictField, KeyField, ListField
  from ....utils import ensure_own_data
  from .dmatrix import ToDMatrix, to_dmatrix
  from .start_tracker import StartTracker
label_desc: Use image node_id 3 for calling the XGBTrain obj's underlying member method code with example usage: obj.__call__() and returns: self