Added ability to generate 1, 2, 3-gram models on a company/date-range basis using <UNK> to represent the initial appearance of a previously unknown word.

src/net/woodyfolsom/cs6601/p3/svc/YahooHeadlineServiceImpl.java

@@ -86,4 +86,10 @@ public class YahooHeadlineServiceImpl implements HeadlineService {
 		String formattedDate = DATE_FORMATTER.format(date);
 		return QUERY_URL.replaceAll(STOCK_SYMBOL_FIELD, stock).replaceAll(STORY_DATE_FIELD, formattedDate);
 	}
+
+	@Override
+	public List<Headline> getHeadlines(String stock, Date startDate,
+			Date endDate) {
+		throw new UnsupportedOperationException("This implementation does not support getting headlines for a date range.");
+	}
 }