CLUSTERSTATUS shards parameter does not accept comma delimited list

According to the documentation for the Collections API, the CLUSTERSTATUS action should accept a comma delimited list of shards if specified. However, when specifying a comma delimited list, it is treated as a single value instead of being parsed into multiple values.

The request

.../collections?action=CLUSTERSTATUS&collection=test_collection&shard=shard1,shard2

yields the response:

{"responseHeader":\{"status":400,"QTime":5}

,"error":{"metadata":["error-class","org.apache.solr.common.SolrException","root-error-class","org.apache.solr.common.SolrException"],"msg":"Collection: test_collection shard: shard1,shard2 not found","code":400}}
instead of locating both shard1 and shard2.