code: public static StringBuilder build(StringBuilder sb, String app, String id, UserChain.Protocol proto, boolean as) {
  		boolean mayAs;
  		if(!(mayAs=sb.length()==0)) {
  			sb.append(',');
  		}
  		sb.append(app);
  		sb.append(':');
  		sb.append(id);
  		sb.append(':');
  		sb.append(proto.name());
  		if(as && mayAs) {
  			sb.append(":AS");
  		}
  		return sb;
  	}
docs: Build an element in the correct format for UserChain.
  Format:<APP>:<ID>:<protocol>[:AS][,<APP>:<ID>:<protocol>]*
  @see UserChain