code: public static String getMethodDescriptor(final Method m) {
          Class<?>[] parameters = m.getParameterTypes();
  		StringBuilder sb = new StringBuilder();
          sb.append('(');
          for (int i = 0; i < parameters.length; ++i) {
              getDescriptor(sb, parameters[i]);
          }
          sb.append(')');
          getDescriptor(sb, m.getReturnType());
          return sb.toString();
      }
docs: Returns the descriptor corresponding to the given method.
  
  @param m
  a {@link Method Method} object.
  @return the descriptor of the given method.