class_docstr: A WindowAssigner assigns zero or more Windows to an element.
  
  In a window operation, elements are grouped by their key (if available) and by the windows to
  which it was assigned. The set of elements with the same key and window is called a pane. When a
  Trigger decides that a certain pane should fire the window to produce output elements for
  that pane.
class_docstr_tok: ["A","WindowAssigner","assigns","zero","or","more","Windows","to","an","element",".","In","a","window","operation",",","elements","are","grouped","by","their","key","(","if","available",")","and","by","the","windows","to","which","it","was","assigned",".","The","set","of","elements","with","the","same","key","and","window","is","called","a","pane",".","When","a","Trigger","decides","that","a","certain","pane","should","fire","the","window","to","produce","output","elements","for","that","pane","."]
docstr: Returns True if elements are assigned to windows based on event time, False otherwise.
code: def is_event_time(self) -> bool:
      """
      Returns True if elements are assigned to windows based on event time, False otherwise.
      """
      pass
  
imports: import math
  from abc import ABC, abstractmethod
  from typing import Generic, List, Any, Iterable, Set
  from pyflink.common.typeinfo import Types
  from pyflink.datastream.state import ValueStateDescriptor, ValueState
  from pyflink.datastream.window import TimeWindow, CountWindow
  from pyflink.fn_execution.table.window_context import Context, W
label_desc: Use image node_id 3 for calling the WindowAssigner obj's underlying member method code with example usage: obj.is_event_time() without return types