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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_dataset(self, dataset_id, project_id=None):
 """Retrieve a dataset if it exists, otherwise return an empty dict. Parameters dataset_id : str Dataset unique id project_id: str, optional The project the dataset is in Returns ------- dict Contains dataset object if it exists, else empty """

        project_id = self._get_project_id(project_id)

        try:            
            dataset = self.bigquery.datasets().get(
                projectId=project_id, datasetId=dataset_id).execute(
                num_retries=self.num_retries)
        except HttpError:
            dataset = {}

        return dataset