public void testWriteNullThirdColumn() throws JsonProcessingException {
final CsvSchema.Builder csvSchemaBuilder = new CsvSchema.Builder();
csvSchemaBuilder.addColumn("timestamp", CsvSchema.ColumnType.STRING);
csvSchemaBuilder.addColumn("value", CsvSchema.ColumnType.NUMBER);
csvSchemaBuilder.addColumn("id", CsvSchema.ColumnType.STRING);
final CsvSchema schema = csvSchemaBuilder.build();
final ObjectWriter writer = new CsvMapper().writer().withSchema(schema);
final String string = writer.writeValueAsString(
ImmutableMap.of("timestamp", 0L, "value", 42));
assertEquals("0,42,\n", string);