# File lib/rubygems/old_format.rb, line 51
    def self.from_io(io, gem_path="(io)")
      format = self.new(gem_path)
      skip_ruby(io)
      format.spec = read_spec(io)
      format.file_entries = []
      read_files_from_gem(io) do |entry, file_data|
        format.file_entries << [entry, file_data]
      end
      format
    end