@Override
                public byte[] next() {
                    if (!hasNext())
                        throw new NoSuchElementException();
                    byte[] cur = next;
                    next = null;
                    return cur;
                }
ClientCompatibilityTest is invoked by the ducktape test client_compatibility_features_test.py to validate
client behavior when various broker versions are in use.  It runs various client operations and tests whether they
are supported or not.
tools/src/main/java/org/apache/kafka/tools/ClientCompatibilityTest.java