build_parallel_executor

# File activesupport/lib/active_support/testing/parallelize_executor.rb, line 35
        def build_parallel_executor
          case parallelize_with
          when :processes
            Testing::Parallelization.new(size)
          when :threads
            ActiveSupport::TestCase.lock_threads = false if defined?(ActiveSupport::TestCase.lock_threads)
            Minitest::Parallel::Executor.new(size)
          else
            raise ArgumentError, "#{parallelize_with} is not a supported parallelization executor."
          end
        end