--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/Content.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.javadoc.internal.doclets.toolkit;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.Objects;
+
+/**
+ * A class to create content for javadoc output pages.
+ *
+ *  <p><b>This is NOT part of any supported API.
+ *  If you write code that depends on this, you do so at your own risk.
+ *  This code and its internal interfaces are subject to change or
+ *  deletion without notice.</b>
+ *
+ * @author Bhavesh Patel
+ */
+public abstract class Content {
+
+    /**
+     * Returns a string representation of the content.
+     *
+     * @return string representation of the content
+     */
+    @Override
+    public String toString() {
+        StringWriter out = new StringWriter();
+        try {
+            write(out, true);
+        } catch (IOException e) {
+            // cannot happen from StringWriter
+            throw new AssertionError(e);
+        }
+        return out.toString();
+    }
+
+    /**
+     * Adds content to the existing content.
+     *
+     * @param content content that needs to be added
+     */
+    public abstract void addContent(Content content);
+
+    /**
+     * Adds a string content to the existing content.
+     *
+     * @param stringContent the string content to be added
+     */
+    public abstract void addContent(CharSequence stringContent);
+
+    /**
+     * Writes content to a writer.
+     *
+     */
+    public abstract boolean write(Writer writer, boolean atNewline) throws IOException ;
+
+    /**
+     * Returns true if the content is empty.
+     *
+     * @return true if no content to be displayed else return false
+     */
+    public abstract boolean isEmpty();
+
+    /**
+     * Returns true if the content is valid.
+     *
+     * @return true if the content is valid else return false
+     */
+    public boolean isValid() {
+        return !isEmpty();
+    }
+
+    /**
+     * Return the number of characters of plain text content in this object
+     * (optional operation.)
+     * @return the number of characters of plain text content in this
+     */
+    public int charCount() {
+        return 0;
+    }
+
+    /**
+     * Checks for null values.
+     *
+     * @param t reference type to check for null values
+     * @return the reference type if not null or else throws a null pointer exception
+     */
+    protected static <T> T nullCheck(T t) {
+        return Objects.requireNonNull(t);
+    }
+}