feat: Add GZIP helper method

Resolves #20 (closed)

testing/src/main/java/org/eclipsefoundation/testing/helpers/SerializationHelpers.java

+/*********************************************************************
+* Copyright (c) 2022 Eclipse Foundation.
+*
+* This program and the accompanying materials are made
+* available under the terms of the Eclipse Public License 2.0
+* which is available at https://www.eclipse.org/legal/epl-2.0/
+*
+* Author: Zachary Sabourin <zachary.sabourin@eclipse-foundation.org>
+*
+* SPDX-License-Identifier: EPL-2.0
+**********************************************************************/
+package org.eclipsefoundation.testing.helpers;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.util.zip.GZIPOutputStream;
+
+/**
+ * Provides serialization helper methods. These method allow encoding values to
+ * various types.
+ */
+public class SerializationHelpers {
+
+    /**
+     * GZIPs the input string and returns a ByteArrayInputStream containgin the
+     * content.
+     * 
+     * @param content The String to convert
+     * @return A ByteArrayInputStream
+     */
+    public static ByteArrayInputStream writeAsGZIP(String content) {
+        try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
+                GZIPOutputStream gzipOut = new GZIPOutputStream(byteOut);) {
+
+            gzipOut.write(content.getBytes());
+            gzipOut.close();
+
+            return new ByteArrayInputStream(byteOut.toByteArray());
+
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+}