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: yaml_source_test.rb
    path of file: ./repos/newrelic-ruby-agent/test/new_relic/agent/configuration
    
    the code of the file until where you have to start completion: # This file is distributed under New Relic's license terms.
# See ht
    
    def test_applying_aliases_has_no_impact_when_aliases_are_absent
      NewRelic::Agent::Configuration::DefaultSource.stub_const(:DEFAULTS, phony_defaults) do
        config = phony_defaults.keys.each_with_object({}) { |k, h| h[k] = true }
        original_config = config.dup.freeze
        phony_source.send(:apply_aliases, config)

        assert_equal original_config, config
      end
    end