in flume-kafka-sink/src/main/java/org/apache/flume/sink/kafka/KafkaSink.java [457:463]
private static Map<CharSequence, CharSequence> toCharSeqMap(Map<String, String> stringMap) {
Map<CharSequence, CharSequence> charSeqMap = new HashMap<CharSequence, CharSequence>();
for (Map.Entry<String, String> entry : stringMap.entrySet()) {
charSeqMap.put(entry.getKey(), entry.getValue());
}
return charSeqMap;
}