question: private void finishInstall ( File tmpFile , Extension extension ) throws IOException { Preconditions . checkNotNull ( tmpFile ) ; Preconditions . checkNotNull ( extension ) ; Preconditions . checkNotNull ( extension . getRowType ( ) ) ; try { File installedFile = getExtensionFile ( extension . getRowType ( ) ) ; FileUtils . moveFile ( tmpFile , installedFile ) ; extensionsByRowtype . put ( extension . getRowType ( ) , extension ) ; } catch ( IOException e ) { log . error ( "Installing extension failed, while trying to move and rename extension file: " + e . getMessage ( ) , e ) ; throw e ; } }
target:  Move and rename temporary file to final version. Update extensions loaded into local lookup.