module RSpec::Matchers

def cover(*values)

### Warning:: Ruby >= 1.9 only

expect(1..10).not_to cover(5) # fails
expect(1..10).not_to cover(11)
expect(1..10).to cover(4, 6, 11) # fails
expect(1..10).to cover(4, 6)
expect(1..10).to cover(5)
@example

and it will only pass if all args are found in Range.
Ranges. You can also pass in multiple args
Passes if actual covers expected. This works for 
def cover(*values)
  BuiltIn::Cover.new(*values)
end if (1..2).respond_to?(:cover?)