code: def get_input_sequence_files(data, default=None):
      
      if "files" not in data or data.get("files") is None:
          file1, file2 = None, None
      elif len(data["files"]) == 2:
          file1, file2 = data["files"]
      else:
          assert len(data["files"]) == 1, data["files"]
          file1, file2 = data["files"][0], None
      return file1, file2
docs: returns the input sequencing files, these can be single or paired FASTQ
      files or BAM files