assert_queries

# File activerecord/lib/active_record/test_case.rb, line 34
    def assert_queries(num = 1)
      $queries_executed = []
      yield
    ensure
      %{ BEGIN COMMIT }.each { |x| $queries_executed.delete(x) }
      assert_equal num, $queries_executed.size, "#{$queries_executed.size} instead of #{num} queries were executed.#{$queries_executed.size == 0 ? '' : "\nQueries:\n#{$queries_executed.join("\n")}"}"
    end