test-matlab-ts-mode--ei-classify-matrix-action-fun result:
---
L19  (non-numeric-m-matrix 1 nil nil 0)       |        ];  mat3 = [ ...
L20  (non-numeric-m-matrix 1)                 |        1,   a+ foo*2; ...
L21  (non-numeric-m-matrix 1)                 |     333, 4; ...
L22  (non-numeric-m-matrix 1)                 |        ]; 
