def METHOD_NAME(opts):
    """
    :return: Path to the .ssh/config file - usually <home>/.ssh/config
    """
    ssh_config_file = opts.get("ssh_config_file")
    if not os.path.isfile(ssh_config_file):
        raise OSError("Cannot find SSH config file")
    if not os.access(ssh_config_file, os.R_OK):
        raise OSError("Cannot access SSH config file: {}".format(ssh_config_file))
    return ssh_config_file