add-imports="from __future__ import annotations" produced syntax error with 'v=""""""\n' as input

[graingert]

on version==5.9.1

input:

v=""""""

expected output:

from __future__ import annotations

v=""""""

actual output:

v=""""""

from __future__ import annotations

[graingert]

another stranger one:
input

v = """
""".split(
    "\n"
)

$ pipx run isort --add-imports='from __future__ import annotations' foo.py

output:

v = """
""".split(
    "\n"
from __future__ import annotations

)