Spring Configuration creating complex data structure with yaml

Using yaml in my Spring-boot application (with snakeyaml dependency 1.16) I am attempting to create a @ConfigurationProperties based off of my application.yml file. I want to create a data structure like the json below which is a Map with String Keys and Array values.

mapName: {
    "key1": ["elem0","elem1"],
    "key2": ["hello","world"]
}

Attempting to create a Spring configuration class as follows

@Component
@ConfigurationProperties(prefix = "channel-broker")
@EnableConfigurationProperties
public class BrokerConfiguration {

    private Map<String, Set<String>> broker = new HashMap<>();

    public Map<String, Set<String>> getBroker() {
        return broker;
    }
}

I have tried the following for my yaml

channel-broker:
    broker: {message-delivery: ['all'], facebook: ['client1']}

Attempt two

channel-broker:
      message-delivery: ['all']
      facebook: ['client1']

Attempt three

channel-broker:
      message-delivery: 
        - ['all']
      facebook: 
        - ['client1']

I have also tried initializing the HashMap in the @ConfigurationProperties class as such ... new HashMap<String, Set<String>> this didn't work either

All attempts result in this error which makes me believe its an error when converting to the object not that there is anything wrong with the yaml syntax.

Caused by: org.springframework.beans.InvalidPropertyException: Invalid property 'brokerTest[message-delivery][0]' of bean class [my.classpackage.clasname]: Property referenced in indexed property path 'brokerTest[message-delivery][0]' is neither an array nor a List nor a Map; returned value was [all]

Is it possible to create such an object? How would I accomplish this

-UPDATE-

If I change the Set to an ArrayList (or List interface) this works but that isn't what I'm looking for. changed to this

private Map<String, ArrayList<String>> brokerTest = new HashMap<>();

but need this doesn't work with Set interface either:

private Map<String, HashSet<String>> brokerTest = new HashMap<>();

Solution

This issue was being caused by the format of the yaml file. The following structure allowed me to build my graph like data structure out of yaml

channel-broker:
   broker:
       message-delivery: 
          all
       facebook: 
          client1,client2

The Set doesn't want anything extra surrounding the key. Note if your Set will contain multiple values you can add a comma to separate them. Just like Json the last element will not have a comma after.