# File lib/minitest/spec.rb, line 159
  def self.it desc, &block
    block ||= proc { skip "(no tests defined)" }

    @specs ||= 0
    @specs += 1

    name = "test_%04d_%s" % [ @specs, desc.gsub(/\W+/, '_').downcase ]

    define_method name, &block

    classes(MiniTest::Spec).each do |mod|
      mod.send :undef_method, name if mod.respond_to? name
    end
  end