How to use the viewport-mercator-project.normalizeViewportProps function in viewport-mercator-project

_applyConstraints(props: ViewportProps): ViewportProps {
    // Ensure zoom is within specified range
    const {maxZoom, minZoom, zoom} = props;
    props.zoom = clamp(zoom, minZoom, maxZoom);

    // Ensure pitch is within specified range
    const {maxPitch, minPitch, pitch} = props;
    props.pitch = clamp(pitch, minPitch, maxPitch);

    Object.assign(props, normalizeViewportProps(props));

    return props;
  }

_applyConstraints(props) {
    // Ensure zoom is within specified range
    const {maxZoom, minZoom, zoom} = props;
    props.zoom = clamp(zoom, minZoom, maxZoom);

    // Ensure pitch is within specified range
    const {maxPitch, minPitch, pitch} = props;
    props.pitch = clamp(pitch, minPitch, maxPitch);

    Object.assign(props, normalizeViewportProps(props));

    return props;
  }

test('normalizeViewportProps', (t) => {
  config.EPSILON = 1e-7;

  for (const [input, expected] of NORMALIZATION_TEST_CASES) {
    const result = normalizeViewportProps(input);

    t.ok(equals(
        Object.keys(expected).map(key => result[key]),
        Object.keys(expected).map(key => expected[key])
      ),
      'correct viewport returned'
    );
  }
  t.end();
});