# File lib/mocha/mock.rb, line 38
38:     def expects(method_name_or_hash, backtrace = nil)
39:       if method_name_or_hash.is_a?(Hash) then
40:         method_name_or_hash.each do |method_name, return_value|
41:           ensure_method_not_already_defined(method_name)
42:           @expectations.add(Expectation.new(self, method_name, backtrace).returns(return_value))
43:         end
44:       else
45:         ensure_method_not_already_defined(method_name_or_hash)
46:         @expectations.add(Expectation.new(self, method_name_or_hash, backtrace))
47:       end
48:     end