wholefile-transformer-lib/src/main/java/com/streamsets/pipeline/stage/processor/transformer/WholeFileTransformerProcessor.java
private DataFileStream<GenericRecord> getFileReader(InputStream is, String sourceFileName) throws StageException {
    try {
      DatumReader<GenericRecord> reader = new GenericDatumReader<>();
      DataFileStream<GenericRecord> fileReader = new DataFileStream<>(is, reader);
      return fileReader;
    } catch (IOException ex) {
      throw new TransformerStageCheckedException(Errors.CONVERT_11, sourceFileName, ex);
    }
  }
private DataFileStream<GenericRecord> getFileReader(InputStream is, String sourceFileName) throws StageException {
    try {
      DatumReader<GenericRecord> reader = new GenericDatumReader<>();
      DataFileStream<GenericRecord> fileReader = new DataFileStream<>(is, reader);
      return fileReader;
    } catch (IOException ex) {
      throw new TransformerStageCheckedException(Errors.CONVERT_11, sourceFileName, ex);
    }
  }
Return the Avro file reader
@param is the {@link java.io.InputStream} input stream of the source Avro file
@param sourceFileName the source Avro file name