java client to treat multi valued parameters differently between null and empty collection

We want to be able to use the Swagger Java generated client to send get requests of the form:

1) /v1/entity
2) /v1/entity?entityId=
3) /v1/entity?entityId=1,2,3

For each of these cases we want the java client call to be

a) ApiClient.getEntity(null)
b) ApiClient.getEntity(Collections.emptyList())
c) ApiClient.getEntity(Arrays.asList(1,2,3))

In the swagger.yaml if the "allowEmptyValue" is set to true then b) should result in 2).

At the moment the swagger generated client does not distinguish between a) and b). If you want to generate a get call of the form shown in 2) you have to do the following:

ApiClient.getEntity(Arrays.asList(""))

Start with the generated Java client's ApiClient.getEntity(null), getEntity(Collections.emptyList()), and getEntity(Arrays.asList(1,2,3)) calls, then inspect how the Swagger YAML allowEmptyValue setting is handled. Verify that null omits the parameter, an empty collection emits entityId=, and populated collections emit comma-separated values.