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: definition_test.rb
    path of file: ./repos/workarea/core/test/lib/workarea/configuration/administrable
    
    the code of the file until where you have to start completion: require 'test_helper'

module Workarea
  module Configuration
    module Administrable
      class DefinitionTest < TestCase
        def test_fieldset
          definition = Definition.new

          assert_equal(1, definition.fieldsets.size)

          fieldset = definition
    
        def test_find_fieldset
          definition = Definition.new

          assert_equal(:application, definition.find_fieldset('application').id)
          assert_equal(:application, definition.find_fieldset(:application).id)

          definition.fieldset(:foo_bar) do
            field :baz, type: :string, default: 'baz'
          end

          assert_equal(:foo_bar, definition.find_fieldset('foo_bar').id)
          assert_equal(:foo_bar, definition.find_fieldset(:foo_bar).id)
          assert_nil(definition.find_fieldset('baz'))
        end