docstr: Get the information about the current transition - tti
code: def _get_trans_info(self, ts, year, fold):
      """Get the information about the current transition - tti"""
      start, end = self.transitions(year)
  
      # With fold = 0, the period (denominated in local time) with the
      # smaller offset starts at the end of the gap and ends at the end of
      # the fold; with fold = 1, it runs from the start of the gap to the
      # beginning of the fold.
      #
      # So in order to determine the DST boundaries we need to know both
      # the fold and whether DST is positive or negative (rare), and it
      # turns out that this boils down to fold XOR is_positive.
      if fold == (self.dst_diff >= 0):
          end -= self.dst_diff
      else:
          start += self.dst_diff
  
      if start < end:
          isdst = start <= ts < end
      else:
          isdst = not (end <= ts < start)
  
      return self.dst if isdst else self.std
  
imports: import bisect
  import calendar
  import collections
  import functools
  import re
  import weakref
  from datetime import datetime, timedelta, tzinfo
  from .None import _common, _tzpath
label_desc: Use image node_id 3 for calling the _TZStr obj's underlying member method code with example usage: obj._get_trans_info(ts, year, fold) and returns: unknown