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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 _throat_props(self):
        r'''
        Helper Function to calculate the throat normal vectors
        '''
        network = self.network
        net_Ts = network.throats(self.name)
        conns = network['throat.conns'][net_Ts]
        p1 = conns[:, 0]
        p2 = conns[:, 1]
        coords = network['pore.coords']
        normals = tr.unit_vector(coords[p2]-coords[p1])
        self['throat.normal'] = normals
        self['throat.centroid'] = (coords[p1] + coords[p2])/2
        self['throat.incenter'] = self['throat.centroid']