docs: public static DMatrix6x6 transpose( DMatrix6x6 input , DMatrix6x6 output ) {
          if( input == null )
              input = new DMatrix6x6();
  
          output.a11 = input.a11;
          output.a12 = input.a21;
          output.a13 = input.a31;
          output.a14 = input.a41;
          output.a15 = input.a51;
          output.a16 = input.a61;
          output.a21 = input.a12;
          output.a22 = input.a22;
          output.a23 = input.a32;
          output.a24 = input.a42;
          output.a25 = input.a52;
          output.a26 = input.a62;
          output.a31 = input.a13;
          output.a32 = input.a23;
          output.a33 = input.a33;
          output.a34 = input.a43;
          output.a35 = input.a53;
          output.a36 = input.a63;
          output.a41 = input.a14;
          output.a42 = input.a24;
          output.a43 = input.a34;
          output.a44 = input.a44;
          output.a45 = input.a54;
          output.a46 = input.a64;
          output.a51 = input.a15;
          output.a52 = input.a25;
          output.a53 = input.a35;
          output.a54 = input.a45;
          output.a55 = input.a55;
          output.a56 = input.a65;
          output.a61 = input.a16;
          output.a62 = input.a26;
          output.a63 = input.a36;
          output.a64 = input.a46;
          output.a65 = input.a56;
          output.a66 = input.a66;
  
          return output;
      }