@Override
            public boolean isOpen() {
                return channel.isOpen();
            }
Test the lazy down-conversion path.

If `overflow` is true, the number of bytes we want to convert is much larger
than the number of bytes we get after conversion. This causes overflow message batch(es) to be appended towards the
end of the converted output.
clients/src/test/java/org/apache/kafka/common/record/LazyDownConversionRecordsTest.java