# File lib/rspec/matchers/exist.rb, line 10
      def matches?(actual)
        super(actual)
        predicates = [:exist?, :exists?].select { |p| actual.respond_to?(p) }
        existance_values = predicates.map { |p| actual.send(p, *expected) }
        uniq_truthy_values = existance_values.map { |v| !!v }.uniq

        case uniq_truthy_values.size
        when 0; raise NoMethodError.new("#{actual.inspect} does not respond to either #exist? or #exists?")
        when 1; existance_values.first
        else raise "#exist? and #exists? returned different values:\n\n" +
          " exist?: #{existance_values.first}\n" +
          "exists?: #{existance_values.last}"
        end
      end