public void removeHeader(Object header){
  if (mHeaders.contains(header)) {
    int position=mHeaders.indexOf(header);
    mHeaders.remove(position);
    notifyItemRemoved(position);
  }
}

public void removeHeader ( Object header ) { if ( mHeaders . contains ( header ) ) { int position = mHeaders . indexOf ( header ) ; mHeaders . remove ( position ) ; notifyItemRemoved ( position ) ; } }
remove a header from the adapter
