modules/jooby-mongodb-rx/src/main/java/org/jooby/mongodb/MongoRx.java
@SuppressWarnings("rawtypes")
  public MongoRx observableAdapter(final Function<Observable, Observable> adapter) {
    this.adapter = toAdapter(requireNonNull(adapter, "Adapter is required."));
    return this;
  }
@SuppressWarnings("rawtypes")
  public MongoRx observableAdapter(final Function<Observable, Observable> adapter) {
    this.adapter = toAdapter(requireNonNull(adapter, "Adapter is required."));
    return this;
  }
Set a {@link ObservableAdapter} to the {@link MongoDatabase} created by this module.

@param adapter An {@link ObservableAdapter}.
@return This module.