You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: test_gem_package_tar_reader_entry.rb
    path of file: ./repos/truffleruby/test/mri/tests/rubygems
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
require_relative "package/tar_test_case"
require "rubygems/package"

c
    
  def test_open_returns_entry
    io = TempIO.new @tar
    header = Gem::Package::TarHeader.from io
    entry = Gem::Package::TarReader::Entry.open header, io
    refute entry.closed?
    assert_equal ?a, entry.getc
    assert_nil entry.close
    assert entry.closed?
  end