code: def write_lockfile(self, content):
          
          s = self._lockfile_encoder.encode(content)
          open_kwargs = {"newline": self._lockfile_newlines, "encoding": "utf-8"}
          with vistir.contextmanagers.atomic_open_for_write(
              self.lockfile_location, **open_kwargs
          ) as f:
              f.write(s)
              # Write newline at end of document. GH-319.
              # Only need '\n' here; the file object handles the rest.
              if not s.endswith(u"\n"):
                  f.write(u"\n")
docs: Write out the lockfile.