code: def toposort(dsk, dependencies=None):
      """Return a list of keys of dask sorted in topological order."""
      return _toposort(dsk, dependencies=dependencies)
  
imports: from __future__ import annotations
  from collections import defaultdict
  from collections.abc import Collection, Iterable, Mapping
  from typing import Any, Literal, TypeVar, cast, overload
  from dask.typing import Graph, Key, NoDefault, no_default
label_desc: Use image node_id 19 for calling a global function with example usage: toposort(dsk, dependencies) and returns: _toposort