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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 format_tsv_line(source, edge, target, value=None, metadata=None):
 """ Render a single line for TSV file with data flow described :type source str :type edge str :type target str :type value float :type metadata str :rtype: str """

    return '{source}\t{edge}\t{target}\t{value}\t{metadata}'.format(
        source=source,
        edge=edge,
        target=target,
        value='{:.4f}'.format(value) if value is not None else '',
        metadata=metadata or ''
    ).rstrip(' \t')