def METHOD_NAME(self, A, b):
    """
    Compute x s.t. Ax = b
    """
    if is_sparse(A) or is_sparse(b):
        A, b = A.tocsc(), b.tocsc()
        x = sparse.COO(scipy.sparse.linalg.spsolve(A, b))
    else:
        x = np.linalg.METHOD_NAME(A, b)
    return x