"""
Lightweight shim for `ddar` used by several tests. When a real `ddar` implementation
is available in other project submodules, Python's import system will prefer that.
This shim provides minimal safe implementations so tests that import `ddar` during
collection won't fail.
"""
from typing import Any, List


def solve(graph: Any, rules: Any, problem: Any) -> Any:
    # Minimal stub: pretend to solve by returning None
    return None


class Solver:
    def __init__(self):
        pass

    def run(self, *args, **kwargs):
        return None


# Export common names used in tests
__all__ = ["solve", "Solver"]