describe("a", function()
  setup(function()
    print("setup for a")
  end)
  it("does a", function()
     print("test for a")
  end)
end)

describe("b ", function()
  setup(function()
    print("setup for b")
  end)
  it("does b", function()
    print("test for b")
  end)
end)

-- ~/programmingStuff/lua $ busted --filter="does b" bust.lua
-- setup for a
-- setup for b
-- test for b
-- ●
-- 1 success / 0 failures / 0 errors / 0 pending : 0.00081 seconds