class RSpec::Matchers::BuiltIn::BePredicate

def failure_to_respond_explanation
  super || if predicate == :true?
             " or perhaps you meant `be true` or `be_truthy`"
           elsif predicate == :false?
             " or perhaps you meant `be false` or `be_falsey`"
           end
end

def predicate
  @predicate ||= :"#{root}?"
end

def predicate_accessible?
  super || really_responds_to?(present_tense_predicate)
end

def predicate_method_name
  actual.respond_to?(predicate) ? predicate : present_tense_predicate
end

def present_tense_predicate
  :"#{root}s?"
end