Correcting prototypes according PEP 484

Author: bigcat88

pillow_heif/_libheif_ctx.py

@@ -5,7 +5,7 @@
 import builtins
 from io import SEEK_SET
 from pathlib import Path
-from typing import Dict, List
+from typing import Dict, List, Optional
 
 from _pillow_heif_cffi import ffi, lib
 
@@ -63,7 +63,7 @@ def __init__(self, compression_format: int = HeifCompressionFormat.HEVC):
         self.encoder = ffi.gc(p_encoder[0], lib.heif_encoder_release)
         # lib.heif_encoder_set_logging_level(self.encoder, 4)
 
-    def set_encoder_parameters(self, enc_params: Dict[str, str], quality: int = None):
+    def set_encoder_parameters(self, enc_params: Dict[str, str], quality: Optional[int] = None):
         if quality is not None:
             if quality == -1:
                 check_libheif_error(lib.heif_encoder_set_lossless(self.encoder, True))

pillow_heif/heif.py

@@ -278,7 +278,7 @@ def _get_pure_data(self):
 class HeifThumbnail(HeifImageBase):
     """Class represents a single thumbnail for a HeifImage."""
 
-    def __init__(self, original_img, reference, thumb_id: int = None):
+    def __init__(self, original_img, reference, thumb_id: Optional[int] = None):
         if isinstance(original_img, HeifImage):
             p_handle = ffi.new("struct heif_image_handle **")
             check_libheif_error(lib.heif_image_handle_get_thumbnail(original_img._handle, thumb_id, p_handle))