code: def get_description(self):
          
          paths = ['bpmn:collaboration/bpmn:participant/bpmn:documentation',
                   'bpmn:collaboration/bpmn:documentation',
                   'bpmn:process/bpmn:documentation']
          for path in paths:
              elm = self.root.find(path, NS)
              if elm is not None and elm.text:
                  return elm.text
docs: Tries to get WF description from 'collabration' or 'process' or 'pariticipant'
  
          Returns str: WF description