code: def endswith(self, suffix, start=None, end=None):
          
          suffix = Bits(suffix)
          start, end = self._validate_slice(start, end)
          if start + suffix.len > end:
              return False
          start = end - suffix.len
          return self._slice(start, end) == suffix
docs: Return whether the current bitstring ends with suffix.
  
          suffix -- The bitstring to search for.
          start -- The bit position to start from. Defaults to 0.
          end -- The bit position to end at. Defaults to self.len.