from typing import Dict


def bigint_func(x: str, _: Dict) -> bool:
    """Tests if the string is a valid bigint"""
    if x == "":
        return True
    x = x.rstrip("0").rstrip(".")
    # rstrip would take 1.1.0.0 -> 1.1, so we do it in two steps. Technically,
    # this would take 1234..0 -> 1234, but that's a problem for future me
    # The solution is to use removesuffix("."), but it was only added in 3.9 :(
    try:
        y = int(x)
        assert -9223372036854775808 <= y <= 9223372036854775807
        return True
    except:  # noqa
        return False