Add annotations to networkx.algorithms.approximation.treewidth (#14983)

Author: lkct

stubs/networkx/networkx/algorithms/approximation/treewidth.pyi

@@ -1,21 +1,25 @@
 from _typeshed import Incomplete
+from collections.abc import Callable, Mapping
+from typing import Generic
 
 from networkx.classes.graph import Graph, _Node
 from networkx.utils.backends import _dispatchable
 
 __all__ = ["treewidth_min_degree", "treewidth_min_fill_in"]
 
 @_dispatchable
-def treewidth_min_degree(G: Graph[_Node]): ...
+def treewidth_min_degree(G: Graph[_Node]) -> tuple[int, Graph[frozenset[_Node]]]: ...
 @_dispatchable
-def treewidth_min_fill_in(G: Graph[_Node]): ...
+def treewidth_min_fill_in(G: Graph[_Node]) -> tuple[int, Graph[frozenset[_Node]]]: ...
 
-class MinDegreeHeuristic:
+class MinDegreeHeuristic(Generic[_Node]):
     count: Incomplete
 
-    def __init__(self, graph) -> None: ...
-    def best_node(self, graph): ...
+    def __init__(self, graph: Graph[_Node]) -> None: ...
+    def best_node(self, graph: Mapping[_Node, set[_Node]]) -> _Node | None: ...
 
-def min_fill_in_heuristic(graph_dict) -> Incomplete | None: ...
+def min_fill_in_heuristic(graph_dict: Mapping[_Node, set[_Node]]) -> _Node | None: ...
 @_dispatchable
-def treewidth_decomp(G: Graph[_Node], heuristic=...) -> tuple[int, Graph[_Node]]: ...
+def treewidth_decomp(
+    G: Graph[_Node], heuristic: Callable[[dict[_Node, set[_Node]]], _Node | None] = ...
+) -> tuple[int, Graph[frozenset[_Node]]]: ...