'Return the correct Docker version(s) for the current OpenShift version.'

def get_required_docker_version(self):

    openshift_version = self.get_openshift_version_tuple()
    earliest = min(self.openshift_to_docker_version)
    latest = max(self.openshift_to_docker_version)
    if (openshift_version < earliest):
        return self.openshift_to_docker_version[earliest]
    if (openshift_version > latest):
        return self.openshift_to_docker_version[latest]
    docker_version = self.openshift_to_docker_version.get(openshift_version)
    if (not docker_version):
        msg = 'There    is    no    recommended    version    of    Docker    for    the    current    version    of    OpenShift:    {}'
        raise OpenShiftCheckException(msg.format('.'.join((str(comp) for comp in openshift_version))))
    return docker_version
