code: def status(self, migration_rqst_id="", block_name="", dataset="", user=""):
          
          try:
              return self.dbsMigrate.listMigrationRequests(migration_rqst_id,
                  block_name, dataset, user)
          except dbsException as de:
              dbsExceptionHandler(de.eCode, de.message, self.logger.exception, de.serverError)
          except Exception as ex:
              sError = "DBSMigrateModle/status. %s\n Exception trace: \n %s." \
                       % (ex, traceback.format_exc() )
  	    if hasattr(ex, 'status') and ex.status == 400:
  		dbsExceptionHandler('dbsException-invalid-input2', str(ex), self.logger.exception, sError)	
              else:
  		dbsExceptionHandler('dbsException-server-error',  str(ex), self.logger.exception, sError)
docs: Interface to query status of a migration request
          In this preference order of input parameters :
              migration_rqst_id, block, dataset, user
              (if multi parameters are provided, only the precedence order is followed)