presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/HivePageSinkMetadataProvider.java/HivePageSinkMetadataProvider/getPartition
class HivePageSinkMetadataProvider:    public Optional<Partition> getPartition(List<String> partitionValues)
    {
        if (!table.isPresent() || table.get().getPartitionColumns().isEmpty()) {
            throw new IllegalArgumentException(
                    format("Unexpected call to getPartition. Table name: %s", schemaTableName));
        }
        Optional<Partition> modifiedPartition = modifiedPartitions.get(partitionValues);
        if (modifiedPartition == null) {
            return delegate.getPartition(identity, schemaTableName.getSchemaName(), schemaTableName.getTableName(), partitionValues);
        }
        else {
            return modifiedPartition;
        }
    }