code: @SuppressWarnings("unchecked")
      public static BasicDBObjectBuilder start(final Map documentAsMap) {
          BasicDBObjectBuilder builder = new BasicDBObjectBuilder();
          Iterator<Map.Entry> i = documentAsMap.entrySet().iterator();
          while (i.hasNext()) {
              Map.Entry entry = i.next();
              builder.add(entry.getKey().toString(), entry.getValue());
          }
          return builder;
      }
docs: Creates an object builder from an existing map of key value pairs.
  
  @param documentAsMap a document in Map form.
  @return the new builder