Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System/sys/system/IO/compression/IDeflater.cs

@@ -0,0 +1,12 @@
+
+using System.Diagnostics.Contracts;
+
+namespace System.IO.Compression {
+
+    internal interface IDeflater : IDisposable {
+        [Pure] bool NeedsInput();
+        void SetInput(byte[] inputBuffer, int startIndex, int count);
+        int GetDeflateOutput(byte[] outputBuffer);
+        bool Finish(byte[] outputBuffer, out int bytesRead);
+    }
+}