code: public Matrix removeRow(int i) {
          if (i >= rows || i < 0) {
              throw new IndexOutOfBoundsException("Illegal row number, must be 0.." + (rows - 1));
          }
  
          Matrix result = blankOfShape(rows - 1, columns);
  
          for (int ii = 0; ii < i; ii++) {
              result.setRow(ii, getRow(ii));
          }
  
          for (int ii = i + 1; ii < rows; ii++) {
              result.setRow(ii - 1, getRow(ii));
          }
  
          return result;
      }
docs: Removes one row from matrix.
  @param i the row index
  @return matrix without row.