code: private String convertMethod(List<String> methodList, boolean negative) {
          boolean first = true;
          StringBuffer methodSB = new StringBuffer();
          for (String method : methodList) {
              if (first) {
                  first = false;
                  if (negative) {
                      methodSB.append("!");
                  }
              } else {
                  methodSB.append(",");
              }
              methodSB.append(method);
          }
          if (tc.isDebugEnabled())
              Tr.debug(tc, "convertMethod : " + methodSB.toString());
          return methodSB.toString();
      }
docs: convert array of method to string