TraversalBuilder and Hop should be able to handle multiple values for a template parameter

With spring-mvc (and other frameworks) it is easy to handle requests where one parameter is used more than once in a single request, such as GET http://my-url.org/my-service?param=value1&param=value2&param=value3. (For instance, using spring-mvc one could use a List for a single parameter with multiple values or a MultiValueMap.)

However, the TraversalBuilder and Hop classes of spring-hateoas store template parameters in a Map and thereby fail to handle the above situation. Could this change, so that clients can handle multiple values?

Start by inspecting the TraversalBuilder and Hop classes mentioned in the issue, focusing on how template parameters are stored and expanded. Reproduce a request containing repeated param values such as value1, value2, and value3; done means clients preserve and handle all values instead of collapsing them into one map entry.