Extension method for `INode.RequiresTime`

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/MaterialGraphPresenter.cs

 
             // Let the node set contain all the nodes that are directly time-dependent.
             m_TimeDependentPresenters.Clear();
-            foreach (var presenter in m_Elements.OfType<MaterialNodePresenter>().Where(x => (x.node is IMayRequireTime) && ((IMayRequireTime)x.node).RequiresTime()))
+            foreach (var presenter in m_Elements.OfType<MaterialNodePresenter>().Where(x => x.node.RequiresTime()))
                 m_TimeDependentPresenters.Add(presenter.node.guid, presenter);
 
             // The wavefront contains time-dependent nodes from which we wish to propagate time-dependency into the

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Util/MaterialNodeExtensions.cs

+using UnityEngine.Graphing;
+
+namespace UnityEngine.MaterialGraph
+{
+    public static class NodeExtensions
+    {
+        public static bool RequiresTime(this INode node)
+        {
+            var timeNode = node as IMayRequireTime;
+            return timeNode != null && timeNode.RequiresTime();
+        }
+    }
+}

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Util/MaterialNodeExtensions.cs.meta

+fileFormatVersion: 2
+guid: 73ed72480b864b078821956f4f00da99
+timeCreated: 1503563173