# File lib/logging/config/yaml_configurator.rb, line 52
    def initialize( io, key  )
      YAML.load_documents(io) do |doc|
        @config = doc[key]
        break if @config.instance_of?(Hash)
      end

      unless @config.instance_of?(Hash)
        raise Error, "Key '#{key}' not defined in YAML configuration"
      end
    end