code: public DrawerBuilder withAdapter(@NonNull FastAdapter<IDrawerItem> adapter) {
          this.mAdapter = adapter;
          //we have to rewrap as a different FastAdapter was provided
          adapter.addAdapter(0, mHeaderAdapter);
          adapter.addAdapter(1, mItemAdapter);
          adapter.addAdapter(2, mFooterAdapter);
          adapter.addExtension(mExpandableExtension);
          return this;
      }
docs: Define a custom Adapter which will be used in the drawer
  NOTE: this is not recommender
  WARNING: if you do this after adding items you will loose those!
  
  @param adapter the FastAdapter to use with this drawer
  @return this