code: def cnst_AT(self, X):
          r
  
          return np.sum(self.cnst_A0T(X), axis=-1) + self.cnst_A1T(X)
docs: r"""Compute :math:`A^T \mathbf{x}` where :math:`A \mathbf{x}` is
          a component of ADMM problem constraint. In this case
          :math:`A^T \mathbf{x} = (\Gamma_0^T \;\; \Gamma_1^T \;\; \ldots
          \;\; I) \mathbf{x}`.