Add new interface for support of layered caching.

Add `SupportsLayeredWheelCache` marker interface that supports
different cache layers setting.

Author: mhbkb

pygradle-plugin/src/main/groovy/com/linkedin/gradle/python/tasks/supports/SupportsLayeredWheelCache.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2016 LinkedIn Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.linkedin.gradle.python.tasks.supports;
+
+import com.linkedin.gradle.python.wheel.WheelCache;
+import org.gradle.api.Task;
+
+
+/**
+ * Marker interface for tasks that support layered WheelCache
+ */
+public interface SupportsLayeredWheelCache extends Task {
+    /**
+     * Sets the project layer WheelCache instance.
+     *
+     * @param wheelCache
+     */
+    void setProjectLayerWheelCache(WheelCache wheelCache);
+
+    /**
+     * Sets the host layer WheelCache instance.
+     *
+     * @param wheelCache
+     */
+    void setHostLayerWheelCache(WheelCache wheelCache);
+
+    /**
+     * @return the project layer WheelCache instance.
+     */
+    WheelCache getProjectLayerWheelCache();
+
+    /**
+     * @return the host layer WheelCache instance.
+     */
+    WheelCache getHostLayerWheelCache();
+}