code: private boolean representsArray(String key) {
  
          int openingBracket = key.indexOf("[");
          int closingBracket = key.indexOf("]");
  
          return closingBracket == key.length() - 1 && openingBracket != -1;
  
      }
docs: Returns true, if key represents an array.
  
  @param key configuration key
  @return true if the config key represents an array, false otherwise.