public String getDeleteTaskLookupStatement() {
        return QueryBuilder.delete()
                .from(keyspace, TABLE_TASK_LOOKUP)
                .where(eq(TASK_ID_KEY, bindMarker()))
                .getQueryString();
    }
@return cql query statement to delete a task_id to workflow_id mapping from the "task_lookup"
    table
cassandra-persistence/src/main/java/com/netflix/conductor/cassandra/util/Statements.java