update

com.unity.uiwidgets/Runtime/material/curves.cs

+using Unity.UIWidgets.animation;
+
+namespace Unity.UIWidgets.material {
+    public partial class material_ {
+        public static readonly Curve standardEasing = Curves.fastOutSlowIn;
+
+        public static readonly Curve accelerateEasing = new Cubic(0.4f, 0.0f, 1.0f, 1.0f);
+
+        public static readonly Curve decelerateEasing = new Cubic(0.0f, 0.0f, 0.2f, 1.0f);
+    }
+}