def key2BSTM(self, key):
trained = (self & key).fetch1()
voxel = key['vx'], key['vy'], key['vz']
b = RankDegenerateBernoulliProcess(voxel, quadratic_channels=key['quadratic_components'],
linear_channels=key['linear_components'],
common_channels=key['common_components'])
b.set_parameters(**trained)
return b