code: function () {
      if (!this.mapper.hasObject(this.modelElement.path())) {
        const resolver = this.node.getKevoreeCore().getResolver();
        return resolver.resolve(this.modelElement)
          .then((Type) => {
            this.log.debug(
              'namespace=' + ModelHelper.getNamespace(this.modelElement.eContainer()) +
              ',hash=' + this.modelElement.hashcode +
              ',name=' + this.modelElement.name +
              ',version=' + this.modelElement.version);
            this.mapper.addEntry(this.modelElement.path(), Type);
          });
      } else {
        // this deploy unit is already installed, move on
        return Promise.resolve();
      }
    }
docs: [description]
  @return {Promise} [description]