Fix dependency issue when installing from PyPI.

arcadeutils/filebytes.py

@@ -1,10 +1,11 @@
 import shutil
 from typing import BinaryIO, Dict, List, Optional, Set, Tuple, Union, overload
+from typing_extensions import Final
 
 
 class FileBytes:
 
-    IO_SIZE: int = 0x8000
+    IO_SIZE: Final[int] = 0x8000
 
     def __init__(self, handle: BinaryIO) -> None:
         self.__handle: BinaryIO = handle

requirements.txt

@@ -0,0 +1 @@
+typing-extensions

setup.py

@@ -8,7 +8,7 @@ with open(os.path.join("arcadeutils", "README.md"), "r", encoding="utf-8") as fh
 
 setup(
     name='arcadeutils',
-    version='0.1.8',
+    version='0.1.9',
     description='Collection of utilities written in Python for working with various arcade binaries.',
     long_description=long_description,
     long_description_content_type="text/markdown",
@@ -20,5 +20,8 @@ setup(
     packages=[
         'arcadeutils',
     ],
+    install_requires=[
+        'typing-extensions',
+    ],
     python_requires=">=3.6",
 )