SAML2 Testing using Soapui

I am a newbie to soap ui. I want to test SAML2 fedaration using SoapUI pro.
Please let me know how can I do this.
Where can I get the WSDL file and which application I can use as the first endpoint.
Enpoint1: will be some aplication
Endpoint2: Will be the system under test.

Have no idea about how to start with. Any suggestions will be really appreciated.

Thanks in advance for your support.