Cannot enabled metrics for JPA units

[domain@localhost:9990 /] /host=master/server=stage1/deployment=jboss-as-kitchensink-jsp.war/subsystem=jpa/hibernate-persistence-unit=jboss-as-kitchensink-jsp.war#primary:write-attribute(name=enabled,value=true)
{
    "outcome" => "success",
    "result" => undefined
}
[domain@localhost:9990 /] /host=master/server=stage1/deployment=jboss-as-kitchensink-jsp.war/subsystem=jpa/hibernate-persistence-unit=jboss-as-kitchensink-jsp.war#primary:read-resource(include-runtime=true)     
{
    "outcome" => "success",
    "result" => {
        "close-statement-count" => 0L,
        "collection-fetch-count" => 0L,
        "collection-load-count" => 0L,
        "collection-recreated-count" => 0L,
        "collection-remove-count" => 0L,
        "collection-update-count" => 0L,
        "completed-transaction-count" => 0L,
        "connect-count" => 0L,
        "enabled" => undefined,
        "entity-delete-count" => 0L,
        "entity-fetch-count" => 0L,
        "entity-insert-count" => 0L,
        "entity-load-count" => 0L,
        "entity-update-count" => 0L,
        "flush-count" => 0L,
        "hibernate-persistence-unit" => "jboss-as-kitchensink-jsp.war#primary",
        "optimistic-failure-count" => 0L,
        "prepared-statement-count" => 0L,
        "query-cache-hit-count" => 0L,
        "query-cache-miss-count" => 0L,
        "query-cache-put-count" => 0L,
        "query-execution-count" => 0L,
        "query-execution-max-time" => 0L,
        "query-execution-max-time-query-string" => "null",
        "second-level-cache-hit-count" => 0L,
        "second-level-cache-miss-count" => 0L,
        "second-level-cache-put-count" => 0L,
        "session-close-count" => 0L,
        "session-open-count" => 0L,
        "successful-transaction-count" => 0L,
        "collection" => undefined,
        "entity" => {"org.jboss.as.quickstarts.kitchensinkjsp.model.Member" => undefined},
        "entity-cache" => {"org.jboss.as.quickstarts.kitchensinkjsp.model.Member" => undefined},
        "query-cache" => undefined
    }
}