new (Gem::Package::TarHeader)

    # File lib/rubygems/package.rb, line 106
        def initialize(vals)
          unless vals[:name] && vals[:size] && vals[:prefix] && vals[:mode]
            raise ArgumentError, ":name, :size, :prefix and :mode required"
          end
          vals[:uid] ||= 0
          vals[:gid] ||= 0
          vals[:mtime] ||= 0
          vals[:checksum] ||= ""
          vals[:typeflag] ||= "0"
          vals[:magic] ||= "ustar"
          vals[:version] ||= "00"
          vals[:uname] ||= "wheel"
          vals[:gname] ||= "wheel"
          vals[:devmajor] ||= 0
          vals[:devminor] ||= 0
          FIELDS.each {|x| instance_variable_set "@#{x.to_s}", vals[x]}
          @empty = vals[:empty]
        end