Import of https://github.com/ciena/voltctl at commit 40d61fbf3f910ed4017cf67c9c79e8e1f82a33a5

Change-Id: I8464c59e60d76cb8612891db3303878975b5416c
diff --git a/pkg/model/devicegroup.go b/pkg/model/devicegroup.go
new file mode 100644
index 0000000..a433a08
--- /dev/null
+++ b/pkg/model/devicegroup.go
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2019-present Ciena Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package model
+
+import (
+	"github.com/jhump/protoreflect/dynamic"
+)
+
+type DeviceGroup struct {
+	Id             string   `json:"id"`
+	LogicalDevices []string `json:"logicaldevices"`
+	Devices        []string `json:"devices"`
+}
+
+func getId(val *dynamic.Message) string {
+	return val.GetFieldByName("id").(string)
+}
+
+func (d *DeviceGroup) PopulateFrom(val *dynamic.Message) {
+	d.Id = val.GetFieldByName("id").(string)
+	logicaldevices := val.GetFieldByName("logical_devices").([]interface{})
+	d.LogicalDevices = make([]string, len(logicaldevices))
+	for i, logicaldevice := range logicaldevices {
+		d.LogicalDevices[i] = getId(logicaldevice.(*dynamic.Message))
+	}
+	devices := val.GetFieldByName("logical_devices").([]interface{})
+	d.Devices = make([]string, len(devices))
+	for i, device := range devices {
+		d.Devices[i] = getId(device.(*dynamic.Message))
+	}
+}