code: def peekDateTime(self):
      # Return the datetime for the next event.
      # This is needed to properly synchronize non-realtime subjects.
      # Return None since this is a realtime subject.
      raise NotImplementedError()
  
imports: import abc
  import six
  from pyalgotrade import dispatchprio
label_desc: Use image node_id 7 for calling the Subject obj's underlying member method code with example usage: obj.peekDateTime() without return types