code: function merge(source, destination) {
    for(var attr in source) {
      if(!destination.hasOwnProperty(attr) && !/\$$/.test(attr)) {
        destination[attr] = source[attr]
      }
    }
  }
docs: Unfortunately, this is mostly for the unit tests to pass.
  The in-memory store behaviour will completely replace an existing object with
  the one being saved. Hence we need to do an in-memory merge before saving.
  Bug opened against seneca: https://github.com/rjrodger/seneca/issues/43