docs: def ensure_us_time_resolution(val):
      """Convert val out of numpy time, for use in to_dict.
      Needed because of numpy bug GH#7619"""
      if np.issubdtype(val.dtype, np.datetime64):
          val = val.astype('datetime64[us]')
      elif np.issubdtype(val.dtype, np.timedelta64):
          val = val.astype('timedelta64[us]')
      return val