lqDecomposition() {
        let {Q, R} = this.adjoint().qrDecomposition();
        return {L: R.adjoint(), Q: Q.adjoint()};
    }
Factors the receiving square matrix into a lower diagonal matrix L times a unitary matrix Q.
@returns {!{L: !Matrix, Q: !Matrix}} where L.times(Q).isEqualTo(this) && Q.isUnitary() && R.isLowerTriangular()