def METHOD_NAME(
    CCT: ArrayLike, cmfs: MultiSpectralDistributions | None = None
) -> NDArrayFloat:
    """
    Return the *CIE UCS* colourspace *uv* chromaticity coordinates from given
    correlated colour temperature :math:`T_{cp}` and colour matching functions
    using the spectral radiance of a blackbody at the given thermodynamic
    temperature.
    Parameters
    ----------
    CCT
        Colour temperature :math:`T_{cp}`.
    cmfs
        Standard observer colour matching functions, default to the
        *CIE 1931 2 Degree Standard Observer*.
    Returns
    -------
    :class:`numpy.ndarray`
        *CIE UCS* colourspace *uv* chromaticity coordinates.
    References
    ----------
    :cite:`CIETC1-482004i`
    Examples
    --------
    >>> CCT_to_uv_Planck1900(6504)  # doctest: +ELLIPSIS
    array([ 0.2004280...,  0.3103334...])
    """
    CCT = as_float_array(CCT)
    cmfs, _illuminant = handle_spectral_arguments(cmfs)
    XYZ = msds_to_XYZ_integration(
        np.transpose(
            planck_law(cmfs.wavelengths * 1e-9, np.ravel(CCT)) * 1e-9
        ),
        cmfs,
        shape=cmfs.shape,
    )
    UVW = XYZ_to_UCS(XYZ)
    uv = UCS_to_uv(UVW)
    return np.reshape(uv, [*list(CCT.shape), 2])