code: private boolean speculateFullAnnotation() {
          state.backtracking++;
          int start = input.mark();
          try {
              exprParser.fullAnnotation( null );
          } catch ( RecognitionException re ) {
              System.err.println( "impossible: " + re );
              re.printStackTrace();
          }
          boolean success = ! state.failed;
          input.rewind( start );
          state.backtracking--;
          state.failed = false;
          return success;
  
      }
docs: Invokes the expression parser, trying to parse the annotation
  as a full java-style annotation
  
  @return true if the sequence of tokens will match the
  elementValuePairs() syntax. false otherwise.