in src/main/java/com/google/cloud/solutions/autotokenize/common/AvroSchemaToCatalogSchema.java [171:187]
private ColumnSchemaFlatKeys processRecord() {
var fieldSchemaAndKeys = extractRecordFields();
var flatKeys =
fieldSchemaAndKeys.stream()
.flatMap(ColumnSchemaFlatKeys::flatKeyEntriesStream)
.distinct()
.collect(toImmutableMap(Map.Entry::getKey, Map.Entry::getValue));
var colSchemas =
fieldSchemaAndKeys.stream()
.map(ColumnSchemaFlatKeys::columnSchema)
.collect(toImmutableList());
var recordSchema = schemaBuilder().addAllSubcolumns(colSchemas).build();
return ColumnSchemaFlatKeys.of(recordSchema, flatKeys);
}