populateAuthTokenHeader = () => {
  return (next) => (action) => {
    if (
      (action.type === ACTIONS.USER_FETCH_SUCCESS || action.type === ACTIONS.AUTHENTICATION_SUCCESS) &&
      action.data.user.has_verified_email === true
    ) {
      const authToken = getAuthToken();
      Lbry.setApiHeader(X_LBRY_AUTH_TOKEN, authToken);
    }

    return next(action);
  };
}
source: the reducer name
property: the property in the reducer-specific state
transform: optional method to modify the value to be stored

See https://github.com/lbryio/lbry-redux/blob/master/src/redux/middleware/shared-state.js for the source
This is based off v0.1
If lbry-redux changes to another version, this code will need to be changed when upgrading