code: private boolean paramAppend(StringBuilder sb, String name, String value, ParameterParser parser) {
          boolean isEdited = false;
          
          if (name != null) {
              sb.append(name);
              isEdited = true;
          }
          
          if (value != null) {
              sb.append(parser.getDefaultKeyValueSeparator());
              sb.append(value);
              isEdited = true;
          }
          
          return isEdited;
      }
docs: Set the name value pair into the StringBuilder. If both name and value is
  null, not to append whole parameter.
  
  @param sb
  @param name Null = not to append parameter.
  @param value null = not to append parameter value.
  @return true = parameter changed.