class RSpec::Matchers::DSL::Matcher

def description(&block)

end
end
"qualify for #{expected}"
description do

match { ... }
RSpec::Matchers.define :qualify_for do |expected|

@example

the description generated by default doesn't suit your needs.
Customize the description to use for one-liners. Only use this when 
def description(&block)
  cache_or_call_cached(:description, &block)
end