docs: public static DMatrixRMaj concatColumnsMulti(DMatrixRMaj ...m ) {
          int rows = 0;
          int cols = 0;
  
          for (int i = 0; i < m.length; i++) {
              rows = Math.max(rows,m[i].numRows);
              cols += m[i].numCols;
          }
          DMatrixRMaj R = new DMatrixRMaj(rows,cols);
  
          int col = 0;
          for (int i = 0; i < m.length; i++) {
              insert(m[i],R,0,col);
              col += m[i].numCols;
          }
  
          return R;
      }