# 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