text: # -*- coding: utf-8 -*-
  """The time slice."""
  
  from __future__ import unicode_literals
  
  
  class TimeSlice(object):
    """Time slice.
  
    The time slice is used to provide a context of events around an event
    of interest.
  
    Attributes:
      duration (int): duration of the time slice in minutes.
      event_timestamp (int): event timestamp of the time slice or None.
    """
  
    _MICRO_SECONDS_PER_MINUTE = 60 * 1000000
  
    def __init__(self, event_timestamp, duration=5):
      """Initializes the time slice.
  
      Args:
        event_timestamp (int): event timestamp of the time slice or None.
        duration (Optional[int]): duration of the time slice in minutes.
            The default is 5, which represent 2.5 minutes before and 2.5 minutes
            after the event timestamp.
      """
      super(TimeSlice, self).__init__()
      self.duration = duration
      self.event_timestamp = event_timestamp
  
    @property
    def end_timestamp(self):
      """int: slice end timestamp or None."""
      if self.event_timestamp:
        return self.event_timestamp + (
            self.duration * self._MICRO_SECONDS_PER_MINUTE)
  
    @property
    def start_timestamp(self):
      """int: slice start timestamp or None."""
      if self.event_timestamp:
        return self.event_timestamp - (
            self.duration * self._MICRO_SECONDS_PER_MINUTE)
  