SoapUI API: Create DataSourceStep

Thanks for the quick reply

I think i should say a little bit more about the project, so that you know what i'd like to achieve:

I'm working on a webservice which uses the SoapUI Pro 5.0.0 library.
The webservice is written in java and one of it's features should be, that for an existing project a datasource step can be created.
I know that the datasource steps are a pro-feature and only SoapUI Pro users can work with these steps.
The users who will use the projects created by my webservice will be owners of pro licences.

So i'd like to use the SoapUI library to create projects which are opened afterwards by SoapUI Pro users.

I figured out by now, that the pro library contains a class called DataSourceStepFactory.
Is this class the one used to create datasource step? And if it is, how do I use it?

I've tried this:

DataSourceStepFactory factory = new DataSourceStepFactory();

TestStepConfig config = factory.createNewTestStep(testCase, "datasource");

testCase.addTestStep(config);

But i got a NullPointerException from the createNewTestStep-method:
java.lang.NullPointerException
at com.eviware.x.form.XFormFactory.createDialogBuilder(XFormFactory.java:19)
at com.eviware.x.form.support.ADialogBuilder.buildDialog(ADialogBuilder.java:60)
at com.eviware.soapui.SoapUIPro.b(SourceFile:440)
at com.eviware.soapui.SoapUIPro.validateLicense(SourceFile:719)
at com.eviware.soapui.SoapUIPro.validateLicense(SourceFile:697)
at com.eviware.soapui.impl.wsdl.teststeps.registry.DataSourceStepFactory.createNewTestStep(SourceFile:36)
at com.wl.soapui.UtilsSoapUI.createDataSourceTestStep(UtilsSoapUI.java:838)
at com.wl.soapui.UtilsSoapUITest.testDataSourceTeststep(UtilsSoapUITest.java:48)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Could you please explain me what I did wrong?
Is this factory the class I need and what parameters do I have to use?

I'm really grateful for any kind of help Thanks in advance!