code: function bindModel(proc, model) {
    const actualModel = model || {};
    proc.model = actualModel;
    proc.logic.model = actualModel;
  
    if (!actualModel.__proc) {
      Object.defineProperty(actualModel, '__proc', {
        value: proc,
        enumerable: false,
        configurable: true
      });
    }
  }
docs: Associate instance of the Process with given model by setting
  hidden `__proc` field in the model. Also set model and shared model,
  
  @private
  @param  {Process} proc
  @param  {Object} model