You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: test_gem_silent_ui.rb
    path of file: ./repos/jruby/test/mri/rubygems
    
    the code of the file until where you have to start completion: # frozen_string
    
  def test_ask
    value = nil
    out, err = capture_output do
      use_ui @sui do
        value = @sui.ask 'Problem?'
      end
    end

    assert_empty out, 'No output'
    assert_empty err, 'No output'

    assert_nil value, 'No value'
  end