enhance graphviz_draw type hint

Author: zen-xu

rustworkx/visualization/graphviz.pyi

@@ -10,17 +10,66 @@ import typing
 from rustworkx.rustworkx import PyGraph, PyDiGraph
 
 if typing.TYPE_CHECKING:
-    from PIL import Image  # type: ignore
+    from PIL.Image import Image
+    Method: typing.TypeAlias = typing.Literal["twopi", "neato", "circo", "fdp", "sfdp", "dot"]
+    ImageType: typing.TypeAlias = typing.Literal[
+        "canon",
+        "cmap",
+        "cmapx",
+        "cmapx_np",
+        "dia",
+        "dot",
+        "fig",
+        "gd",
+        "gd2",
+        "gif",
+        "hpgl",
+        "imap",
+        "imap_np",
+        "ismap",
+        "jpe",
+        "jpeg",
+        "jpg",
+        "mif",
+        "mp",
+        "pcl",
+        "pdf",
+        "pic",
+        "plain",
+        "plain-ext",
+        "png",
+        "ps",
+        "ps2",
+        "svg",
+        "svgz",
+        "vml",
+        "vmlzvrml",
+        "vtx",
+        "wbmp",
+        "xdor",
+        "xlib",
+    ]
 
 _S = typing.TypeVar("_S")
 _T = typing.TypeVar("_T")
 
+@typing.overload
 def graphviz_draw(
     graph: PyDiGraph[_S, _T] | PyGraph[_S, _T],
     node_attr_fn: typing.Callable[[_S], dict[str, str]] | None = ...,
     edge_attr_fn: typing.Callable[[_T], dict[str, str]] | None = ...,
     graph_attr: dict[str, str] | None = ...,
-    filename: str | None = ...,
-    image_type: str | None = ...,
-    method: str | None = ...,
-) -> Image | None: ...
+    filename: None = ...,
+    image_type: ImageType | None = ...,
+    method: Method | None = ...,
+) -> Image: ...
+@typing.overload
+def graphviz_draw(
+    graph: PyDiGraph[_S, _T] | PyGraph[_S, _T],
+    node_attr_fn: typing.Callable[[_S], dict[str, str]] | None = ...,
+    edge_attr_fn: typing.Callable[[_T], dict[str, str]] | None = ...,
+    graph_attr: dict[str, str] | None = ...,
+    filename: str = ...,
+    image_type: ImageType | None = ...,
+    method: Method | None = ...,
+) -> None: ...