Using block Gauss-Seidel Iterative Method.

I am interested in solving a large system with block Gauss-Seidel Iterative Method.
Is there any way in NGSolve to use the block Gauss-Seidel Iterative Method in solving the system Ax=b ?.

Further explanations can be found in the attached file.

I am grateful for any explanation.

Attachment: block_Gauss_Seidel.pdf