expects (Mocha::Mock)

        # File lib/mocha/mock.rb, line 40
    40:     def expects(method_name_or_hash, backtrace = nil)
    41:       if method_name_or_hash.is_a?(Hash) then
    42:         method_name_or_hash.each do |method_name, return_value|
    43:           ensure_method_not_already_defined(method_name)
    44:           @expectations.add(Expectation.new(self, method_name, backtrace).returns(return_value))
    45:         end
    46:       else
    47:         ensure_method_not_already_defined(method_name_or_hash)
    48:         @expectations.add(Expectation.new(self, method_name_or_hash, backtrace))
    49:       end
    50:     end