def __init__(self, package, version):
        """Construct a new requirement.

        :param package: the package name.
        :param version: a semver compatible version specification.
        """
        self.package = package
        self.version = version
        if self.version and not re.match(r"[<=>~]", version[:2]):
            self.version = "=={}".format(self.version)
def test_regex_flags_good_input():
    cases = (
        'abcd',
        'ABCabc',
        'ABC',
    )

    case_insensitive = inputs.regex(r'^[A-Z]+$', re.IGNORECASE)

    for value in cases:
        yield assert_equal, case_insensitive(value), value