docs: @Pure
  	public boolean isIdentity() {
          if (this.isIdentity == null) {
              this.isIdentity = MathUtil.isEpsilonZero(this.curvilineTranslation)
                      && MathUtil.isEpsilonZero(this.curvilineTranslation);
          }
          return this.isIdentity.booleanValue();
  	}