docs: def hash(self):
          """Hash value based on file name and .ini file content"""
          if self._hash is None:
              # Only hash _camera.ini and _para.ini
              fsh = [self.path.with_name(self._mid + "_camera.ini"),
                     self.path.with_name(self._mid + "_para.ini")]
              tohash = [hashfile(f) for f in fsh]
              tohash.append(self.path.name)
              # Hash a maximum of ~1MB of the tdms file
              tohash.append(hashfile(self.path, blocksize=65536, count=20))
              self._hash = hashobj(tohash)
          return self._hash