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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def loopangle(c1: Dict[str, Any]) -> xarray.Dataset: """ loop over "ANGLE" """

    angles = np.atleast_1d(c1['angle'])
    TR = xarray.Dataset(coords={'wavelength_nm': None, 'angle_deg': angles})

    for a in angles:
        c = c1.copy()
        c['angle'] = a
        TR = TR.merge(golowtran(c))

    return TR