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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_models(self, uniprot_acc):
 """Return all available models for a UniProt accession number. Args: uniprot_acc (str):
 UniProt ACC/ID Returns: dict: All available models in SWISS-MODEL for this UniProt entry """

        if uniprot_acc in self.all_models:
            return self.all_models[uniprot_acc]
        else:
            log.error('{}: no SWISS-MODELs available'.format(uniprot_acc))
            return None