/subsystem=elytron/constant-permission-mapper=test2:add(permissions=[{class-name="abc",action="",target-name=""}])

{
    "address" => [
        ("subsystem" => "elytron"),
        ("constant-permission-mapper" => "test2")
    ],
    "operation" => "add",
    "permissions" => [{
        "class-name" => "abc",
        "action" => undefined,        <=== should be ""
        "target-name" => undefined    <=== should be ""
    }]
}