def METHOD_NAME(name=None, amplitude=1, sigma=0.1, center=None,
             shape='gaussian', sigma_params=None, **kws):
    """create an XRF Peak
    Parameters:
    -----------
      name:  name of peak -- may be used for auto-setting center
             'Fe Ka1',  'Pb Lb1', etc
      amplitude:
      center:
      sigma:
      shape   peak shape (gaussian, voigt, lorentzian)
    For all the options described as **value or parameter** either a
    numerical value or a Parameter (as created by param()) can be given.
    Returns:
    ---------
        an XRFPeak Group.
    """
    return XRFPeak(name=name, amplitude=amplitude, sigma=sigma, center=center,
                    shape=shape, sigma_params=sigma_params)