code: private void checkJsDocInBlockComments(String fileName) {
      if (!compiler.getOptions().preservesDetailedSourceInfo()) {
        // Comments only available if preservesDetailedSourceInfo is true.
        return;
      }
  
      for (Comment comment : compiler.getComments(fileName)) {
        if (comment.type == Comment.Type.BLOCK) {
          if (COMMENT_PATTERN.matcher(comment.value).find()) {
            compiler.report(
                JSError.make(
                    fileName,
                    comment.location.start.line + 1,
                    comment.location.start.column,
                    JSDOC_IN_BLOCK_COMMENT));
          }
        }
      }
    }
docs: Checks for block comments (e.g. starting with /*) that look like they are JsDoc, and thus
  should start with /**.