geojson.parse ignores alt value

[idokleinman]

Given let pointObj = {lat: 1.1, lon: 2.2, alt: 3.3, test: 'test'}; let point = geojson.parse(pointObj, { Point: ['lat', 'lon', 'alt'] });

point will equal { type: 'Point', coordinates: [ 2.2, 1.1 ] } alt value has been dropped. Why?