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_collation.rb
    path of file: ./repos/sqlite3-ruby/test
    
    the code of the file until where you have to start completion: require "helper"

module SQLite3
  class TestCollation < SQLite3::TestCase
    class Comparator
      attr_reader :calls
      def initialize
        @calls = []
      end

      def compare left, right
        @calls << [left, right]
        left <=> right
      end
    end

    def setup
      @db = SQL
    
    def test_encoding_default_internal
      warn_before = $-w
      $-w = false
      before_enc = Encoding.default_internal

      Encoding.default_internal = "EUC-JP"
      comparator = Comparator.new
      @db.collation "foo", comparator
      @db.execute("select data from ex order by 1 collate foo")

      a, b = *comparator.calls.first

      assert_equal Encoding.find("EUC-JP"), a.encoding
      assert_equal Encoding.find("EUC-JP"), b.encoding
    ensure
      Encoding.default_internal = before_enc
      $-w = warn_before
    end