code: private static String getMethodSignature(final String returnType, final String methodName, final Class<?>[] argTypes) {
          final StringBuilder sb = new StringBuilder();
          if (returnType != null) {
              sb.append(returnType);
              sb.append(" ");
          }
          sb.append(methodName);
          sb.append("(");
          if (argTypes != null) {
              for (int i = 0; i < argTypes.length; i++) {
                  if (i > 0) {
                      sb.append(", ");
                  }
                  sb.append(argTypes[i].getName());
              }
          }
          sb.append(")");
          return sb.toString();
      }
docs: Creates a textual representation of the method.
  
  @param returnType
  Return type of the method - Can be <code>null</code>.
  @param methodName
  Name of the method - Cannot be <code>null</code>.
  @param argTypes
  The list of parameters - Can be <code>null</code>.
  
  @return Textual signature of the method.