def get( key, default=nil )
    key = normalize_key(key)
    value = @hash.fetch( key, nil )
    value = @config.header( key ) if value.nil?   # try lookup in config properties next
    if value.nil?
      default
    else
      value
    end
  end
def get( key, default=nil )
    key = normalize_key(key)
    value = @hash.fetch( key, nil )
    value = @config.header( key ) if value.nil?   # try lookup in config properties next
    if value.nil?
      default
    else
      value
    end
  end
todo: rename get to fetch??