add SubText.groupCount()

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@30578 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/MarkupText.java

@@ -181,6 +181,14 @@ public class MarkupText extends AbstractMarkupText {
             return text.substring(start(groupIndex),end(groupIndex));
         }
 
+        /**
+         * How many captured groups are in this subtext.
+         * @since 1.357
+         */
+        public int groupCount() {
+            return groups.length / 2;
+        }
+
         /**
          * Replaces the group tokens like "$0", "$1", and etc with their actual matches.
          */