def lookup(feature, name)
      value = @hash[feature]
      value = value[name] if value.is_a? Hash
      fail IndexError, "No CmdRef defined for #{feature}, #{name}" if value.nil?
      value
    end
def lookup(feature, name)
      value = @hash[feature]
      value = value[name] if value.is_a? Hash
      fail IndexError, "No CmdRef defined for #{feature}, #{name}" if value.nil?
      value
    end
Get the command reference