docs: def copy(self, dst, **kwargs):
          """Copy file to a new destination.
  
          Returns JSON Patch with proposed change pointing to new copy.
          """
          _fs, filename = opener.parse(self.uri)
          _fs_dst, filename_dst = opener.parse(dst)
          copyfile(_fs, filename, _fs_dst, filename_dst, **kwargs)
          return [{'op': 'replace', 'path': self.pointer, 'value': dst}]