[rspec-users] something.should_be_open blows up?

[Pat Maddox]

context "A new Foo"
  specify "should be open" do
    Foo.new.should_be_open
  end
end

ArgumentError in 'A new Foo should be open'
wrong number of arguments (0 for 1)
./foo_spec.rb:9:

class Foo
  def open?; true; end
end

What's the deal with that?  I looked in the RDoc and nothing seems to
define open?.  I can get around it for now by doing the opposite
(should_not_be_closed), but that seems sorta weird.  Anyone else have
issues?

Pat