return the old result_links default (#5)

Return the old result_links default, make the type optional, & I'm pretty sure the original problem is that add_file_links can't take a None, so these statements should be in the body of the if-statement that ensures it is not None

Signed-off-by: wyattscarpenter <[email protected]>

Author: wyattscarpenter

src/databricks/sql/utils.py

@@ -7,7 +7,7 @@
 from collections.abc import Iterable
 from decimal import Decimal
 from enum import Enum
-from typing import Any, Dict, List, Union
+from typing import Any, Dict, List, Optional, Union
 import re
 
 import lz4.frame
@@ -134,7 +134,7 @@ def __init__(
         schema_bytes,
         max_download_threads: int,
         start_row_offset: int = 0,
-        result_links: List[TSparkArrowResultLink] = [],
+        result_links: Optional[List[TSparkArrowResultLink]] = None,
         lz4_compressed: bool = True,
         description: List[List[Any]] = None,
     ):
@@ -161,17 +161,17 @@ def __init__(
                 start_row_offset
             )
         )
-        for result_link in result_links:
-            logger.debug(
-                "- start row offset: {}, row count: {}".format(
-                    result_link.startRowOffset, result_link.rowCount
+        if result_links is not None:
+            for result_link in result_links:
+                logger.debug(
+                    "- start row offset: {}, row count: {}".format(
+                        result_link.startRowOffset, result_link.rowCount
+                    )
                 )
+            self.download_manager = ResultFileDownloadManager(
+                self.max_download_threads, self.lz4_compressed
             )
-
-        self.download_manager = ResultFileDownloadManager(
-            self.max_download_threads, self.lz4_compressed
-        )
-        self.download_manager.add_file_links(result_links)
+            self.download_manager.add_file_links(result_links)
 
         self.table = self._create_next_table()
         self.table_row_index = 0