[
    (src: "{{~foo~}}", exp: [(Expr((true, true), (("foo"), (lo:3, hi:6))), (lo: 0, hi:9))]),
    (src: "{{~ foo~}}", exp: [(Expr((true, true), (("foo"), (lo:4, hi:7))), (lo: 0, hi:10))]),
    (src: "{{~ foo}}", exp: [(Expr((true, false), (("foo"), (lo:4, hi:7))), (lo: 0, hi:9))]),
    (src: "{{foo   ~}}", exp: [(Expr((false, true), (("foo"), (lo:2, hi:5))), (lo: 0, hi:11))]),
    (src: "{{~{foo }~}}", exp: [(Safe((true, true), (("foo"), (lo:4, hi:7))), (lo: 0, hi:12))]),
    (src: "{{{foo }~}}", exp: [(Safe((false, true), (("foo"), (lo:3, hi:6))), (lo: 0, hi:11))]),
]