def METHOD_NAME(
    uv: ArrayLike,
    uv_c: ArrayLike,
    L_a: ArrayLike,
    method: Literal["VAC", "VCC"] | str = "VCC",
) -> NDArrayFloat:
    """
    Return the *HKE* factor for luminous colours using *Nayatani (1997)* method.
    Parameters
    ----------
    uv
        *CIE uv* chromaticity coordinates of samples.
    uv_c
        *CIE uv* chromaticity coordinates of reference white.
    L_a
        Adapting luminance in :math:`cd/m^2`.
    method
        Which estimation method to use, *VCC* or *VAC*.
    Returns
    -------
    :class:`numpy.ndarray`
        Luminance factor (:math:`\\Gamma`) value(s) computed with Nayatani
        luminous colour estimation method.
    References
    ----------
    :cite:`Nayatani1997`
    Examples
    --------
    >>> import colour
    >>> white = colour.xy_to_Luv_uv(colour.temperature.CCT_to_xy_CIE_D(6504))
    >>> colours = colour.XYZ_to_xy(
    ...     [colour.wavelength_to_XYZ(430 + i * 50) for i in range(5)]
    ... )
    >>> L_adapting = 65
    >>> HelmholtzKohlrausch_effect_luminous_Nayatani1997(  # doctest: +ELLIPSIS
    ...     colour.xy_to_Luv_uv(colours), white, L_adapting
    ... )
    array([ 7.4460471...,  2.4767159...,  1.4723422...,  0.7938695...,  \