old_contents: from scipy.sparse import csr_matrix, csc_matrix
  from scipy.sparse.linalg import spsolve
  from openpnm.solvers import DirectSolver
  
  
  class ScipySpsolve(DirectSolver):
  
      def solve(self, A, b, **kwargs):
          if not isinstance(A, (csr_matrix, csc_matrix)):
              A = A.tocsr()
          return spsolve(A, b)
  
new_contents: from scipy.sparse import csr_matrix, csc_matrix
  from scipy.sparse.linalg import spsolve
  from openpnm.solvers import DirectSolver
  
  
  class ScipySpsolve(DirectSolver):
  
      def solve(self, A, b, **kwargs):
          if not isinstance(A, (csr_matrix, csc_matrix)):
              A = A.tocsr()
          # TODO: solver.solve should return (x, info) not just x
          return spsolve(A, b)
  
subject: Add a TODO to solvers.scipy