code: def cancel(self, workflow_id):
          
          self.logger.debug('Canceling workflow: ' + workflow_id)
          url = '%(wf_url)s/%(wf_id)s/cancel' % {
              'wf_url': self.workflows_url, 'wf_id': workflow_id
          }
          r = self.gbdx_connection.post(url, data='')
          r.raise_for_status()
docs: Cancels a running workflow.
  
             Args:
                 workflow_id (str): Workflow id.
  
             Returns:
                 Nothing