Rotate an n x n integer matrix by 90 degrees clockwise. You must rotate it in place , modifying the input matrix directly instead of allocating a second matrix. Input format The input is a single argument [matrix] , where matrix is a JSON 2-D array, e.g. [[[1,2,3],[4,5,6],[7,8,9]]] . The graded answer is the matrix after your method mutates it; any value your method returns is ignored.