def get_process_rca(self, pid=None):
        '''
        get_process_rca(self, pid=None)

        Get the RCA tree of a given failed process. The RCA tree contains all failed child processes that caused the failure of the given process.

        :Parameters:
        * *pid* (`string`) -- Identifier of an existing process

        '''
        pid = self._get_pid(pid)
        return self._call_rest_api('get', '/processes/'+pid+'/rca', error='Failed to fetch process information')