Conditionally compile for iOS

Assets/Scenes/ARCollaborationData/CollaborativeSession.cs

 using UnityEngine;
-using Unity.iOS.Multipeer;
+
+#if UNITY_IOS && !UNITY_EDITOR
+using Unity.iOS.Multipeer;
+#endif
+[RequireComponent(typeof(ARSession))]
-    ARSession m_ARSession;
+    string m_SessionName;
-    public ARSession arSession
+    public string sessionName
-        get { return m_ARSession; }
-        set { m_ARSession = value; }
+        get { return m_SessionName; }
+        set { m_SessionName = value; }
-    [SerializeField]
-    string m_SessionName;
+    ARSession m_ARSession;
-    public string sessionName
+    void Start()
-        get { return m_SessionName; }
-        set { m_SessionName = value; }
+        // Unconditionally compiled Start method so that
+        // we get the enabled checkbox in the Editor
+#if UNITY_IOS && !UNITY_EDITOR
     MCSession m_MCSession;
 
     ARKitSessionSubsystem GetSubsystem()
 
     void Awake()
     {
+        m_ARSession = GetComponent<ARSession>();
         m_MCSession = new MCSession(SystemInfo.deviceName, m_SessionName);
     }
 
     {
         m_MCSession.Dispose();
     }
+#endif
 }