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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_missing_references(client):
 """Find missing references."""

    from renku.models.refs import LinkReference

    missing = [
        ref for ref in LinkReference.iter_items(client)
        if not ref.reference.exists()
    ]

    if not missing:
        return True

    click.secho(
        WARNING + 'There are missing references.'
        '\n  (use "git rm <name>" to clean them)\n\n\t' + '\n\t  '.join(
            click.style(str(ref.path), fg='yellow') + ' -> ' +
            click.style(str(ref.reference), fg='red') for ref in missing
        ) + '\n'
    )
    return False