code: def _release_lock(self):
          
          if not self._has_lock():
              return
  
          # if someone removed our file beforhand, lets just flag this issue
          # instead of failing, to make it more usable.
          lfp = self._lock_file_path()
          try:
              # on bloody windows, the file needs write permissions to be removable.
              # Why ...
              if os.name == 'nt':
                  os.chmod(lfp, 0777)
              # END handle win32
              os.remove(lfp)
          except OSError:
              pass
          self._owns_lock = False
docs: Release our lock if we have one