public Builder unpackFile(String nameInApk,String destFileName){
  unpackers.add(new ExistenceCheckingUnpacker(nameInApk,destFileName));
  return this;
}

public Builder unpackFile ( String nameInApk , String destFileName ) { unpackers . add ( new ExistenceCheckingUnpacker ( nameInApk , destFileName ) ) ; return this ; }
adds a file for unpacking . content of extracted file is not checked on each start against content of the file bundled in apk .
