code: static LocalSubmissionFromCS fromSubmissionParameterFiles(final File localJobSubmissionParametersFile,
                                                              final File localAppSubmissionParametersFile)
        throws IOException {
      final AvroLocalAppSubmissionParameters localAppSubmissionParameters;
  
      final AvroLocalJobSubmissionParameters localJobSubmissionParameters;
  
      try (final FileInputStream fileInputStream = new FileInputStream(localJobSubmissionParametersFile)) {
        final JsonDecoder decoder = DecoderFactory.get().jsonDecoder(
            AvroLocalJobSubmissionParameters.getClassSchema(), fileInputStream);
        final SpecificDatumReader<AvroLocalJobSubmissionParameters> reader =
            new SpecificDatumReader<>(AvroLocalJobSubmissionParameters.class);
        localJobSubmissionParameters = reader.read(null, decoder);
      }
  
      try (final FileInputStream fileInputStream = new FileInputStream(localAppSubmissionParametersFile)) {
        final JsonDecoder decoder = DecoderFactory.get().jsonDecoder(
            AvroLocalAppSubmissionParameters.getClassSchema(), fileInputStream);
        final SpecificDatumReader<AvroLocalAppSubmissionParameters> reader =
            new SpecificDatumReader<>(AvroLocalAppSubmissionParameters.class);
        localAppSubmissionParameters = reader.read(null, decoder);
      }
  
      return new LocalSubmissionFromCS(localJobSubmissionParameters, localAppSubmissionParameters);
    }
docs: Takes the local job submission configuration file, deserializes it, and creates submission object.