@Test
public void bigIntToByteArray_small() throws Exception {

  int expectedSize = 2048;
  BigInteger smallInt = BigInteger.valueOf(42L);
  byte[] smallIntBytes = RsaKem.bigIntToByteArray(smallInt, expectedSize);
  assertThat(smallIntBytes).hasLength(expectedSize);
  assertThat(new BigInteger(1, smallIntBytes)).isEqualTo(smallInt);
}