How to use the big-integer.PETABYTE function in big-integer

const SOTRAGE_OBJ_KEYS = [
    'total',
    'used',
    'used_other',
    // 'used_reduced',
    'free',
    'reserved',
    'unavailable_free',
    'unavailable_used',
    'limit',
    'alloc',
    'real',
];

BigInteger.PETABYTE = new BigInteger(PETABYTE);

// We are overriding BigInteger.prototype.toJSON to make sure that JSON.stringify({ size: bigint }) will behave nicely
// however BigInteger creates 3 prototypes internally (Integer, SmallInteger, BigInteger)
// and writes the 'toJSON' property explicitly for all of them, we have to overwrite all 3.
const IntegerPrototype = BigInteger.prototype;
const BigIntegerPrototype = Object.getPrototypeOf(BigInteger.PETABYTE.multiply(BigInteger.PETABYTE));
const SmallIntegerPrototype = Object.getPrototypeOf(BigInteger.zero);
IntegerPrototype.toJSON = bigint_to_json_method;
BigIntegerPrototype.toJSON = bigint_to_json_method;
SmallIntegerPrototype.toJSON = bigint_to_json_method;

/**
 * @this {BigInteger}
 */
function bigint_to_json_method() {
    return bigint_to_json(this);