docs: public T concatColumns( SimpleBase ...matrices ) {
          convertType.specify0(this,matrices);
          T A = convertType.convert(this);
  
          int numCols = A.numCols();
          int numRows = A.numRows();
          for (int i = 0; i < matrices.length; i++) {
              numRows = Math.max(numRows,matrices[i].numRows());
              numCols += matrices[i].numCols();
          }
  
          SimpleMatrix combined = SimpleMatrix.wrap(convertType.commonType.create(numRows,numCols));
  
          A.ops.extract(A.mat,0,A.numRows(),0,A.numCols(),combined.mat,0,0);
          int col = A.numCols();
          for (int i = 0; i < matrices.length; i++) {
              Matrix m = convertType.convert(matrices[i]).mat;
              int cols = m.getNumCols();
              int rows = m.getNumRows();;
              A.ops.extract(m,0,rows,0,cols,combined.mat,0,col);
              col += cols;
          }
  
          return (T)combined;
      }