code: public Matrix transpose() {
          Matrix result = blankOfShape(columns, rows);
          MatrixIterator it = result.iterator();
  
          while (it.hasNext()) {
              it.next();
              int i = it.rowIndex();
              int j = it.columnIndex();
              it.set(get(j, i));
          }
  
          return result;
      }
docs: Transposes this matrix.
  
  @return the transposed matrix