Restructure Cloud Events support to optionally support Cloud Events SDK

spring-cloud-function-core/src/main/java/org/springframework/cloud/function/core/FunctionInvocationHelper.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.cloud.function.core;
+
+
+/**
+ *
+ * @author Oleg Zhurakousky
+ *
+ */
+public interface FunctionInvocationHelper<I> {
+
+	boolean isRetainOuputAsMessage(I input);
+
+	I preProcessInput(I input, Object inputConverter);
+
+	I postProcessResult(I input, Object result);
+}