docs: private View configureHeader(WrapperView wv, final int position) {
  		View header = wv.mHeader == null ? popHeader() : wv.mHeader;
  		header = mDelegate.getHeaderView(position, header, wv);
  		if (header == null) {
  			throw new NullPointerException("Header view must not be null.");
  		}
  		//if the header isn't clickable, the listselector will be drawn on top of the header
  		header.setClickable(true);
  		header.setOnClickListener(new OnClickListener() {
  
  			@Override
  			public void onClick(View v) {
  				if(mOnHeaderClickListener != null){
  					long headerId = mDelegate.getHeaderId(position);
  					mOnHeaderClickListener.onHeaderClick(v, position, headerId);
  				}
  			}
  		});
  		return header;
  	}