public MongoDBSource<T> build() {
        configFactory.validate();
        return new MongoDBSource<>(configFactory, checkNotNull(deserializer));
    }
Build the {@link MongoDBSource}.

@return a MongoDBParallelSource with the settings made for this builder.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/mongodb-cdc/src/main/java/org/apache/inlong/sort/cdc/mongodb/source/MongoDBSourceBuilder.java