@Test
  public void int64() throws IOException {
    BsonInt32 value = new BsonInt32(64);
    check(Jsons.readerAt(value).peek()).is(JsonToken.NUMBER);
    check(Jsons.readerAt(new BsonInt64(64)).nextInt()).is(64);
    check(Jsons.readerAt(new BsonInt64(64)).nextLong()).is(64L);
    check(Jsons.readerAt(new BsonInt64(64)).nextDouble()).is(64D);
    check(Jsons.readerAt(new BsonInt64(64)).nextString()).is("64");
  }
Validate type conversion between BSON and gson-JSON ({@link com.google.gson.stream.JsonToken}).
mongo/test/org/immutables/mongo/bson4gson/TypeConversionTest.java