def get_version(vms, owner_name, version_name):
    """Get an existing branch version by name

    Args:
      vms (arcgis.features._version.VersionManager): VersionManager object
      owner_name (str): The owner of the branch version to search for
      version_name (str): The name of the branch version to search for
    Returns:
      The fully qualified version name (`owner.version_name`) string
    """

    _version = [
        x
        for x in vms.all
        if x.properties.versionName.lower() == f"{owner_name}.{version_name}".lower()
    ]
    fq_version_name = _version[0].properties.versionName
    return fq_version_name