class_docstr: TriggerContext is a utility for handling Trigger invocations. It can be reused by setting the
  key and window fields. No internal state must be kept in the TriggerContext.
class_docstr_tok: ["TriggerContext","is","a","utility","for","handling","Trigger","invocations",".","It","can","be","reused","by","setting","the","key","and","window","fields",".","No","internal","state","must","be","kept","in","the","TriggerContext","."]
code: def on_merge(self):
      self._trigger.on_merge(self.window, self)
  
imports: from abc import ABC, abstractmethod
  from typing import Generic, TypeVar, List, Iterable
  from pyflink.common.constants import MAX_LONG_VALUE
  from pyflink.datastream.state import StateDescriptor, State, ValueStateDescriptor, ListStateDescriptor, MapStateDescriptor
  from pyflink.datastream.window import TimeWindow, CountWindow
  from pyflink.fn_execution.datastream.process.timerservice_impl import LegacyInternalTimerServiceImpl
  from pyflink.fn_execution.coders import from_type_info, MapCoder, GenericArrayCoder
  from pyflink.fn_execution.internal_state import InternalMergingState
label_desc: Use image node_id 6 for calling the TriggerContext obj's underlying member method code with example usage: obj.on_merge() without return types