def METHOD_NAME(monkeypatch):
    import shutil
    pkgs = ["a", "b", "c"]
    with monkeypatch.context() as m:
        m.setattr(shutil, "which", lambda exe: None)
        assert pkgs == find_missing_executables(pkgs)
    with monkeypatch.context() as m:
        m.setattr(shutil, "which", lambda exe: "/bin")
        assert [] == find_missing_executables(pkgs)