question: set the columns value . concode_field_sep List<String> streamNames concode_elem_sep List<String> columns concode_elem_sep String name concode_elem_sep List<String> partitionKeyList concode_elem_sep Boolean isUnique concode_elem_sep Integer indexId concode_elem_sep USqlDistributionInfo distributionInfo concode_elem_sep List<USqlDirectedColumn> indexKeys concode_elem_sep UUID partitionFunction concode_elem_sep Boolean isColumnstore concode_field_sep USqlIndex withPartitionKeyList concode_elem_sep List<String> streamNames concode_elem_sep USqlIndex withIsUnique concode_elem_sep List<String> columns concode_elem_sep USqlIndex withIndexKeys concode_elem_sep USqlIndex withIsColumnstore concode_elem_sep List<String> partitionKeyList concode_elem_sep Boolean isUnique concode_elem_sep USqlIndex withPartitionFunction concode_elem_sep USqlDistributionInfo distributionInfo concode_elem_sep Boolean isColumnstore concode_elem_sep USqlIndex withDistributionInfo concode_elem_sep USqlIndex withIndexId concode_elem_sep USqlIndex withStreamNames concode_elem_sep String name concode_elem_sep Integer indexId concode_elem_sep USqlIndex withName concode_elem_sep List<USqlDirectedColumn> indexKeys concode_elem_sep UUID partitionFunction
target: USqlIndex function ( List < String > arg0 ) { this . columns = arg0 ; return this ; }