Create a dataset.

def CreateDataset(self):
    """Create a dataset."""
    body = {
        "datasetReference": {
            "datasetId": self.dataset_id,
            "description": "Data exported from GRR",
            "friendlyName": "GRRExportData",
            "projectId": self.project_id
        }
    }
    result = self.service.datasets().insert(
        projectId=self.project_id, body=body).execute()
    self.datasets[self.dataset_id] = result
    return result