* @param examples
* @return
* @throws Exception
*/
protected Filter getEmoticonsFilter(ExampleSet examples) throws Exception {
StringToDictionaryVector filter = new StringToDictionaryVector();
filter.setAttributeNamePrefix(EMOTICON_FEATURE_PREFIX);
filter.setTermList(emoticonDictionary);
filter.setStringAttribute(ExampleSet.MESSAGE_ATTR_NAME);
filter.setWordsToKeep(100);
//filter.setMinTermFreq(10);
filter.setDoNotOperateOnPerClassBasis(true);
filter.setOutputWordCounts(true);
filter.setInputFormat(examples.getInstances());
Instances filtered = Filter.useFilter(examples.getInstances(), filter);
examples.setInstances(filtered);
return filter;
}