@Test
  void emptyJsonObject() throws JsonParseException {
    BsonParser p = Parsers.createParser("{}");
    assertNull(p.currentToken());
    assertNull(p.getCurrentName());
    assertToken(JsonToken.START_OBJECT, p.nextToken());
    assertToken(JsonToken.START_OBJECT, p.currentToken());
    assertNull(p.getCurrentName());
    assertToken(JsonToken.END_OBJECT, p.nextToken());
    assertToken(JsonToken.END_OBJECT, p.currentToken());
    assertNull(p.getCurrentName());
    assertNull(p.nextToken());
    assertNull(p.currentToken());
    assertNull(p.nextFieldName());
    assertNull(p.getCurrentName());
  }
Check {@link BsonParser} call by call using low-level stream API
criteria/mongo/test/org/immutables/criteria/mongo/bson4jackson/BsonParserTreeTest.java