Enforcing the unionOf domains


When defining the following relationship in Designer:

We observe it is translated as an intersection of domains:

<tag:stardog:designer:model:hasTestRun> a owl:ObjectProperty ;
    rdfs:domain <tag:stardog:designer:model:TestCycle> , <tag:stardog:designer:model:TestPlan> ;
    rdfs:label "hasTestRun" ;
    rdfs:range <tag:stardog:designer:model:TestRun> .

Which implies that once a subject has the property "hasTestRun", it is an member of all the classes "TestCycle" and "TestPlan".

Is there any way to enforce the "or" behavior (i.e., unionOf) so that: if you are subject of "hasTestRun", you are a member of class "TestCycle" or "TestPlan"?