UI 자동화를 위해 바인딩 기능 구현

- 유니티 에셋 인증 오류로 meta 재생성

Packages/com.unity.inputsystem/InputSystem/Utilities/Observables/WhereObservable.cs

@@ -0,0 +1,48 @@
+using System;
+
+namespace UnityEngine.InputSystem.Utilities
+{
+    internal class WhereObservable<TValue> : IObservable<TValue>
+    {
+        private readonly IObservable<TValue> m_Source;
+        private readonly Func<TValue, bool> m_Predicate;
+
+        public WhereObservable(IObservable<TValue> source, Func<TValue, bool> predicate)
+        {
+            m_Source = source;
+            m_Predicate = predicate;
+        }
+
+        public IDisposable Subscribe(IObserver<TValue> observer)
+        {
+            return m_Source.Subscribe(new Where(this, observer));
+        }
+
+        private class Where : IObserver<TValue>
+        {
+            private WhereObservable<TValue> m_Observable;
+            private readonly IObserver<TValue> m_Observer;
+
+            public Where(WhereObservable<TValue> observable, IObserver<TValue> observer)
+            {
+                m_Observable = observable;
+                m_Observer = observer;
+            }
+
+            public void OnCompleted()
+            {
+            }
+
+            public void OnError(Exception error)
+            {
+                Debug.LogException(error);
+            }
+
+            public void OnNext(TValue evt)
+            {
+                if (m_Observable.m_Predicate(evt))
+                    m_Observer.OnNext(evt);
+            }
+        }
+    }
+}