code: public Offering getOffering(String offeringName) {
          BasicDBObject query = new BasicDBObject("offering_name", offeringName);
          FindIterable<Document> cursor = this.offeringsCollection.find(query);
  
          return Offering.fromDB(cursor.first());
      }
docs: Get an offering
  
  @param offeringName the name of the offering
  @return the offering identified by offeringId