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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 check_siblings(graph, outputs):
 """Check that all outputs have their siblings listed."""

    siblings = set()
    for node in outputs:
        siblings |= graph.siblings(node)

    siblings = {node.path for node in siblings}
    missing = siblings - {node.path for node in outputs}

    if missing:
        msg = (
            'Include the files above in the command '
            'or use the --with-siblings option.'
        )
        raise click.ClickException(
            'There are missing output siblings:\n\n'
            '\t{0}\n\n{1}'.format(
                '\n\t'.join(click.style(path, fg='red') for path in missing),
                msg,
            ),
        )
    return outputs