question: @ SuppressWarnings ( "deprecation" ) private < T > String generateTestFile ( String filename , List < T > elems , AvroCoder < T > coder , String codec ) throws IOException { File tmpFile = tmpFolder . newFile ( filename ) ; String path = tmpFile . toString ( ) ; FileOutputStream os = new FileOutputStream ( tmpFile ) ; DatumWriter < T > datumWriter = coder . createDatumWriter ( ) ; try ( DataFileWriter < T > writer = new DataFileWriter < > ( datumWriter ) ) { writer . setCodec ( CodecFactory . fromString ( codec ) ) ; writer . create ( coder . getSchema ( ) , os ) ; for ( T elem : elems ) { writer . append ( elem ) ; } } return path ; }
target:  Generates an input Avro file containing the given records in the temporary directory and returns the full path of the file.