code: def tile(cls, op):
      raise NotSupportTile("StartTracker is a chunk op")
  
file_path: mars/mars/learn/contrib/xgboost/start_tracker.py
imports: from threading import Thread
  from ....None import opcodes
  from ....core import NotSupportTile
  from ....serialization.serializables import Int32Field
  from ....utils import to_binary
  from ...operands import LearnOperand, LearnOperandMixin, OutputType
label_desc: Use image node_id 2 for calling the StartTracker obj's underlying member method code with example usage: obj.tile(cls, op) without return types