code: public float get(int row, int col) {
          if (row < 0 || row > 3) {
              throw new IndexOutOfBoundsException("Index: " + row + ", Size: 4");
          }
          if (col < 0 || col > 3) {
              throw new IndexOutOfBoundsException("Index: " + col + ", Size: 4");
          }
  
          return m_data[row * 4 + col];
      }
docs: Gets an element of the matrix.
  
  @param row
  the row
  @param col
  the column
  @return the element at the given position