in java/dataflow-connector-examples/src/main/java/com/google/cloud/bigtable/dataflow/example/CsvImport.java [81:86]
public MutationTransform(CSVFormat csvFormat, String bigTableFamilyName, List<String> csvHeaders, String rowKeyColumnName) {
this.csvFormat = csvFormat;
this.bigTableFamilyNameBytes = bigTableFamilyName.getBytes(StandardCharsets.UTF_8);
this.csvHeaders = csvHeaders.toArray(new String[0]);
this.rowKeyColumnName = isBlank(rowKeyColumnName) ? csvHeaders.get(0) : rowKeyColumnName;
}