_createAssigner.js

exportdefaultfunctioncreateAssigner(keysFunc, defaults) {returnfunction(obj) {varlength =arguments.length;if(defaults) obj =Object(obj);if(length <2|| obj ==null)returnobj;for(varindex =1; index < length; index++) {varsource =arguments[index],
          keys =keysFunc(source),
          l = keys.length;for(vari =0; i < l; i++) {varkey = keys[i];if(!defaults || obj[key] ===void0) obj[key] = source[key];
      }
    }returnobj;
  };
}