code: def __str__(self):
      mg_str = "mg" if self.mg else "sg"
      return f"rmat_{mg_str}_{self._scale}_{self._edgefactor}"
  
imports: import pytest
  import numpy
  import pytest_benchmark
  import rmm
  import dask_cudf
  from pylibcugraph.testing import gen_fixture_params_product
  import cugraph
  import cugraph.dask
  from cugraph.structure.number_map import NumberMap
  from cugraph.generators import rmat
  from cugraph.testing import utils, mg_utils
  from cugraph.utilities.utils import is_device_version_less_than
  from cugraph_benchmarking.params import directed_datasets, undirected_datasets, managed_memory, pool_allocator
label_desc: Use image node_id 2 for calling the RmatDataset obj's underlying member method code with example usage: obj.__str__() and returns: str, mg_str, str, self, str, self