UI 자동화를 위해 바인딩 기능 구현

- 유니티 에셋 인증 오류로 meta 재생성

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

@@ -0,0 +1,57 @@
+using System;
+
+namespace UnityEngine.InputSystem.Utilities
+{
+    internal class TakeNObservable<TValue> : IObservable<TValue>
+    {
+        private IObservable<TValue> m_Source;
+        private int m_Count;
+
+        public TakeNObservable(IObservable<TValue> source, int count)
+        {
+            m_Source = source;
+            m_Count = count;
+        }
+
+        public IDisposable Subscribe(IObserver<TValue> observer)
+        {
+            return m_Source.Subscribe(new Take(this, observer));
+        }
+
+        private class Take : IObserver<TValue>
+        {
+            private IObserver<TValue> m_Observer;
+            private int m_Remaining;
+
+            public Take(TakeNObservable<TValue> observable, IObserver<TValue> observer)
+            {
+                m_Observer = observer;
+                m_Remaining = observable.m_Count;
+            }
+
+            public void OnCompleted()
+            {
+            }
+
+            public void OnError(Exception error)
+            {
+                Debug.LogException(error);
+            }
+
+            public void OnNext(TValue evt)
+            {
+                if (m_Remaining <= 0)
+                    return;
+
+                m_Remaining--;
+                m_Observer.OnNext(evt);
+
+                if (m_Remaining == 0)
+                {
+                    m_Observer.OnCompleted();
+                    m_Observer = default;
+                }
+            }
+        }
+    }
+}