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_sha256.rb
    path of file: ./repos/linguist/test
    
    the code of the file until where you have to start completion: require_relative "./helper"

class TestSHA256 < Minitest::Test
  include Linguist

  def test_hexdigest_string
    assert
    
  def test_hexdigest_integer
    # Ruby 2.4.0 merged Bignum and Fixnum into Integer which means we get different digests
    if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new("2.4.0")
      assert_equal "e2e98cd680460c0cecd76714d94e601be9b629ad16ae45251fa30366f62007bb", SHA256.hexdigest(1)
      assert_equal "88159e413c4a97194ee0d8b082ebfd54ce3f9985b58270d3bf59a6e6186f8da6", SHA256.hexdigest(2)
    else
      assert_equal "d9af1c504ce3dc080973d6de94d44884482fcee3ff04fd430c5aba2e4d1ba2cd", SHA256.hexdigest(1)
      assert_equal "1a4dfbfcf67bc80f3dbade7083386362d8f40db225cbd8e41e61199599f334c3", SHA256.hexdigest(2)
    end