code: public boolean invert() {
          double determinant = determinant();
          if (Math.abs(determinant) <= Double.MIN_VALUE) {
              return false;
          }
  
          double t00 = m00;
          double t01 = m01;
          double t02 = m02;
          double t10 = m10;
          double t11 = m11;
          double t12 = m12;
  
          m00 =  t11 / determinant;
          m10 = -t10 / determinant;
          m01 = -t01 / determinant;
          m11 =  t00 / determinant;
          m02 = (t01 * t12 - t11 * t02) / determinant;
          m12 = (t10 * t02 - t00 * t12) / determinant;
  
          return true;
      }
docs: Invert this matrix. Implementation stolen from OpenJDK.
  @return true if successful