code: private String combine(String org, String add) {
  		if (null == org) {
  			return add;
  		}
  		if (null == add || org.equals(add) || org.startsWith(add + ", ") || org.endsWith(", " + add)) {
  			return org;
  		}
  		return org + ", " + add;
  	}
docs: Combine user information strings.
  <p/>
  Extra information is appended (separated by a comma) if not yet present in the string.
  
  @param org
  base string to append to (avoiding duplication).
  @param add
  string to add
  @return org + ", " + add