I have constructed a tool that could generate sequence diagrams from Java source codes. The resulting sequence diagrams are represented using standard XMI format of UML sequence diagram. 

In order to check whether my tool could produce the correct representations of programs, I need to visualize my output in an existing visualization tool? 

I tried ArguUML, Enterprise Architect,  Visual Paradigm, Trace Modeler, and Altova UModel, but unfortunately they could not do the job.

Any advice about a suitable tool?

Appreciated.