code: function getContext(seneca) {
    var transactionId = seneca.fixedargs.tx$;
    var context = seneca.fixedargs.context$;
  
    if (typeof context === 'undefined') {
      try {
        context = seneca.fixedargs.context$ = JSON.parse(URLSafeBase64.decode(transactionId).toString('utf8'));
        debug('context loaded from tx$ and cached in context$', transactionId, context);
      } catch (error) {
        context = null;
        debug('context cannot be loaded from tx$', transactionId, error);
      }
    } else {
      debug('context loaded from context$', transactionId, context);
    }
  
    return context;
  }
docs: Loads the context from the seneca transaction ID.
  
  @param {seneca} seneca The seneca object, which is the context of a running action.
  @returns {Object} A context object