code: protected String appendDelimiter(String attribute) {
  
          if (CmsStringUtil.isNotEmpty(attribute)) {
              if (!attribute.startsWith(" ")) {
                  // add a delimiter space between the beginning button HTML and the button tag attributes
                  return " " + attribute;
              } else {
                  return attribute;
              }
          }
  
          return "";
      }
docs: Appends a space char. between tag attributes.<p>
  
  @param attribute a tag attribute
  
  @return the tag attribute with a leading space char