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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 get_subspace(self, dims):
        '''
        Extracts subspace from the reference of a list of variables in the inputs
        of the model.
        '''
        subspace = []
        k = 0
        for variable in self.space_expanded:
            if k in dims:
                subspace.append(variable)
            k += variable.dimensionality_in_model
        return subspace