public String getUpdateWorkflowStatement() {
        return QueryBuilder.update(keyspace, TABLE_WORKFLOWS)
                .with(set(PAYLOAD_KEY, bindMarker()))
                .where(eq(WORKFLOW_ID_KEY, bindMarker()))
                .and(eq(SHARD_ID_KEY, 1))
                .and(eq(ENTITY_KEY, ENTITY_TYPE_WORKFLOW))
                .and(eq(TASK_ID_KEY, ""))
                .getQueryString();
    }
@return cql query statement to update a workflow in the "workflows" table
cassandra-persistence/src/main/java/com/netflix/conductor/cassandra/util/Statements.java