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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_input_sequence_files(data, default=None):
 """ returns the input sequencing files, these can be single or paired FASTQ files or BAM files """

    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