in src/internal/qs/utils.ts [38:47]
function array_to_object(source: any[], options: { plainObjects: boolean }) {
const obj = options && options.plainObjects ? Object.create(null) : {};
for (let i = 0; i < source.length; ++i) {
if (typeof source[i] !== 'undefined') {
obj[i] = source[i];
}
}
return obj;
}