Example wired for Spring Testing doesn't work wit DelegateExecution. Example

ProcessExpressions.registerCallActivityMock(DELIVERY_PROCESS_KEY)
        // any onExecution doesn't work
        .onExecutionAddVariable("some_var", "value")
        .onExecutionDo(execution -> {
            //...
        })
        .deploy(rule);

[main] ERROR org.camunda.bpm.engine.context - ENGINE-16004 Exception while closing command context: Unknown property used in expression: ${addVariablesServiceMock_802ce91d}. Cause: Cannot resolve identifier 'addVariablesServiceMock_802ce91d'