"""
Lightweight shim for `graph` used by trace_back tests. This provides minimal
APIs used by tests so imports succeed during test collection.
"""
from typing import Any, List, Tuple


class Graph:
    def __init__(self):
        self.nodes = []
        self.edges = []

    @staticmethod
    def build_problem(problem: Any, defs: Any) -> Tuple[Any, Any]:
        # Return a trivial graph and mapping for tests
        return Graph(), {}


def names2nodes(args: List[Any]) -> List[int]:
    return list(range(len(args)))


__all__ = ["Graph", "names2nodes"]