docs: public static void multAddColA(DMatrixSparseCSC A , int colA ,
                                     double alpha,
                                     DMatrixSparseCSC C, int mark,
                                     double x[] , int w[] ) {
          int idxA0 = A.col_idx[colA];
          int idxA1 = A.col_idx[colA+1];
  
          for (int j = idxA0; j < idxA1; j++) {
              int row = A.nz_rows[j];
  
              if( w[row] < mark ) {
                  if( C.nz_length >= C.nz_rows.length ) {
                      C.growMaxLength(C.nz_length *2+1,true);
                  }
  
                  w[row] = mark;
                  C.nz_rows[C.nz_length] = row;
                  C.col_idx[mark] = ++C.nz_length;
                  x[row] = A.nz_values[j]*alpha;
              } else {
                  x[row] += A.nz_values[j]*alpha;
              }
          }
      }