class DEBUGGER__::Config

def append_config key, val
  conf = config.dup
  if CONFIG_SET[key]
    if CONFIG_SET[key][2] == :path
      conf[key] = [*conf[key], *parse_config_value(key, val)];
    else
      raise "not an Array type: #{key}"
    end
  else
    raise "Unknown configuration: #{key}"
  end
  update conf
end