anchor.diff:      import java.util.Collections;
       import java.util.Arrays;
       import java.util.stream.IntStream;
  +    import org.apache.groovy.util.Maps;
  +    import static org.apache.groovy.parser.antlr4.SemanticPredicates.*;
   }
   
   @members {
  
positive.code:         }
      }
  
      private static final Map<String, String> PAREN_MAP = Collections.unmodifiableMap(new HashMap<String, String>() {
          {
              put("(", ")");
              put("[", "]");
              put("{", "}");
          }
      });
  
      protected void enterParenCallback(String text) {}
  
  
negative.code: }
  
  @header {
      import java.util.Deque;
      import java.util.ArrayDeque;
      import java.util.Map;
  