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 find_first_remote_branch(remotes: Sequence['Remote'], branch_name: str) -> 'RemoteReference':
    """Find the remote branch matching the name of the given branch or raise InvalidGitRepositoryError"""
    for remote in remotes:
        try:
            return remote.refs[branch_name]
        except IndexError:
            continue
        # END exception handling
    # END for remote
    raise InvalidGitRepositoryError("Didn't find remote branch '%r' in any of the given remotes" % branch_name)