# File lib/new_relic/agent/configuration/manager.rb, line 37
        def add_config_for_testing(source, level=0)
          raise 'Invalid config type for testing' unless [Hash, DottedHash].include?(source.class)
          invoke_callbacks(:add, source)
          @configs_for_testing << [source.freeze, level]
          reset_cache
          log_config(:add, source)
        end