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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 from_dict(cls, d):
 """ Create from dict. Args: A dict with all data for a band structure object. Returns: A BandStructure object """

        labels_dict = d['labels_dict']
        projections = {}
        structure = None
        if isinstance(list(d['bands'].values())[0], dict):
            eigenvals = {Spin(int(k)): np.array(d['bands'][k]['data'])
                         for k in d['bands']}
        else:
            eigenvals = {Spin(int(k)): d['bands'][k] for k in d['bands']}
        if 'structure' in d:
            structure = Structure.from_dict(d['structure'])
        if d.get('projections'):
            projections = {Spin(int(spin)): np.array(v)
                           for spin, v in d["projections"].items()}

        return BandStructure(
            d['kpoints'], eigenvals,
            Lattice(d['lattice_rec']['matrix']), d['efermi'],
            labels_dict, structure=structure, projections=projections)