--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/lib/jdk/test/lib/jfr/EventTypePrototype.java	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2016, 2018, 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.test.lib.jfr;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import jdk.jfr.AnnotationElement;
+import jdk.jfr.Name;
+import jdk.jfr.ValueDescriptor;
+
+public final class EventTypePrototype {
+    private final List<ValueDescriptor> fields;
+    private final List<AnnotationElement> annotations;
+    private final String name;
+
+    public EventTypePrototype(String name, List<AnnotationElement> as, List<ValueDescriptor> fields) {
+        this.annotations = new ArrayList<>(as);
+        this.annotations.add(new AnnotationElement(Name.class, name));
+        this.fields = fields;
+        this.name = name;
+    }
+
+    public EventTypePrototype(String name) {
+        this(name, new ArrayList<>(), new ArrayList<>());
+    }
+
+    public int getFieldIndex(String key) {
+        int index = 0;
+        for (ValueDescriptor f : fields) {
+            if (f.getName().equals(key)) {
+                return index;
+            }
+            index++;
+        }
+        throw new NoSuchFieldError(key);
+    }
+
+    public void addField(ValueDescriptor fieldDescriptor) {
+        fields.add(fieldDescriptor);
+    }
+
+    public void addAnnotation(AnnotationElement annotation) {
+        annotations.add(annotation);
+    }
+
+    public List<ValueDescriptor> getFields() {
+        return fields;
+    }
+
+    public List<AnnotationElement> getAnnotations() {
+        return annotations;
+    }
+
+    public String getName() {
+        return name;
+    }
+}