def METHOD_NAME(key: str, with_variance: bool = False) -> Variable:
    """
    Returns the CODATA recommended value with unit of the requested physical constant.
    :param key: Key of the requested constant. See `scipy.constants.physical_constants <https://docs.scipy.org/doc/scipy/reference/constants.html#scipy.constants.physical_constants>`_ for an overview.
    :param with_variance: Optional, if True, the uncertainty if the constant is
                          included as the variance. Default is False.
    :returns: Scalar variable with unit and optional variance.
    :rtype: Variable
    """
    from scipy.constants import METHOD_NAME as _cd
    value, unit, uncertainty = _cd[key]
    args = {'value': value, 'unit': unit.replace(' ', '*')}
    if with_variance:
        stddev = uncertainty
        args['variance'] = stddev * stddev
    return as_const(scalar(**args))