Fields fields = reader.fields();
final Terms fieldTerms = fields.terms(getFieldNames().indexName());
if (fieldTerms instanceof FieldReader) {
final Stats stats = ((FieldReader) fieldTerms).getStats();
long totalTermBytes = stats.totalTermBytes;
if (logger.isTraceEnabled()) {
logger.trace("totalTermBytes: {}, terms.size(): {}, terms.getSumDocFreq(): {}",
totalTermBytes, terms.size(), terms.getSumDocFreq());
}