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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 _context_json(name):
 """Return JSON-LD string for given context name."""

    from renku.models import provenance

    cls = getattr(provenance, name)
    return {
        '@context': cls._jsonld_context,
        '@type': cls._jsonld_type,
    }