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: tc_timezone_transition.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/tzinfo-1.2.3/test
    
    the code of the file until where you have to start completion: require File.join(File.expand_path(File.dirname(__FILE__)), 'test_utils')
require 'date'

include TZInfo

class TCTimezoneTransition < Minitest::Test
  
  class TestTimezoneTransition < TimezoneTransition
    def
    
  def test_local_start_at_before_epoch
    t = TestTimezoneTransition.new(TimezoneOffset.new(-7200, 3600, :TDT),
      TimezoneOffset.new(-7200, 0, :TST), 1800)
    
    if RubyCoreSupport.time_supports_negative
      assert(TimeOrDateTime.new(-1800).eql?(t.local_start_at))
    else
      assert(TimeOrDateTime.new(DateTime.new(1969, 12, 31, 23, 30, 0)).eql?(t.local_start_at))
    end