FIX: Fix None handling in get_range_async

Author: nmacholl

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.15.2 - TBD
+
+#### Bug Fixes
+- Fixed and issue where the `end` parameter in `timeseries.get_range_async` did not support a value of `None`
+
 ## 0.15.1 - 2023-07-06
 
 #### Bug fixes

databento/historical/api/timeseries.py

@@ -102,7 +102,6 @@ def get_range(
         data: dict[str, object | None] = {
             "dataset": validate_semantic_string(dataset, "dataset"),
             "start": start_valid,
-            "end": end_valid,
             "symbols": ",".join(symbols_list),
             "schema": str(schema_valid),
             "stype_in": str(stype_in_valid),
@@ -114,6 +113,8 @@ def get_range(
         # Optional Parameters
         if limit is not None:
             data["limit"] = str(limit)
+        if end is not None:
+            data["end"] = end_valid
 
         return self._stream(
             url=self._base_url + ".get_range",
@@ -196,7 +197,6 @@ async def get_range_async(
         data: dict[str, object | None] = {
             "dataset": validate_semantic_string(dataset, "dataset"),
             "start": start_valid,
-            "end": end_valid,
             "symbols": ",".join(symbols_list),
             "schema": str(schema_valid),
             "stype_in": str(stype_in_valid),
@@ -208,6 +208,8 @@ async def get_range_async(
         # Optional Parameters
         if limit is not None:
             data["limit"] = str(limit)
+        if end is not None:
+            data["end"] = end_valid
 
         return await self._stream_async(
             url=self._base_url + ".get_range",