export function nToHex <ExtToBn extends ToBn | ToBigInt> (value?: ExtToBn | BN | bigint | number | null, { bitLength = -1, isLe = false, isNegative = false }: NumberOptions = {}): HexString {
  return u8aToHex(nToU8a(value || 0, { bitLength, isLe, isNegative }));
}