public boolean hasRoomFor(long timestamp, byte[] key, byte[] value, Header[] headers) {
        return hasRoomFor(timestamp, wrapNullable(key), wrapNullable(value), headers);
    }
Check if we have room for a new record containing the given key/value pair. If no records have been
appended, then this returns true.
clients/src/main/java/org/apache/kafka/common/record/MemoryRecordsBuilder.java