diff -r b2fd2388dd46 -r 4e29b285c723 langtools/test/tools/javac/lambda/lambdaExecution/TBlock.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/lambda/lambdaExecution/TBlock.java	Tue Nov 20 09:58:55 2012 -0800
@@ -0,0 +1,36 @@
+/**
+ * Performs operations upon an input object which may modify that object and/or
+ * external state (other objects).
+ *
+ * <p>All block implementations are expected to:
+ * <ul>
+ * <li>When used for aggregate operations upon many elements blocks
+ * should not assume that the {@code apply} operation will be called upon
+ * elements in any specific order.</li>
+ * </ul>
+ *
+ * @param <T> The type of input objects to {@code apply}.
+ */
+public interface TBlock<T> {
+
+    /**
+     * Performs operations upon the provided object which may modify that object
+     * and/or external state.
+     *
+     * @param t an input object
+     */
+    void apply(T t);
+
+    /**
+     * Returns a Block which performs in sequence the {@code apply} methods of
+     * multiple Blocks. This Block's {@code apply} method is performed followed
+     * by the {@code apply} method of the specified Block operation.
+     *
+     * @param other an additional Block which will be chained after this Block
+     * @return a Block which performs in sequence the {@code apply} method of
+     * this Block and the {@code apply} method of the specified Block operation
+     */
+    public default TBlock<T> chain(TBlock<? super T> other) {
+        return (T t) -> { apply(t); other.apply(t); };
+    }
+}