class_docstr: Generates random Erdos-Renyi (ER) graphs.
  See :meth:`~torch_geometric.utils.erdos_renyi_graph` for more information.
  
  Args:
      num_nodes (int): The number of nodes.
      edge_prob (float): Probability of an edge.
code: def __call__(self) -> Data:
      edge_index = erdos_renyi_graph(self.num_nodes, self.edge_prob)
      return Data(num_nodes=self.num_nodes, edge_index=edge_index)
  
imports: from torch_geometric.data import Data
  from torch_geometric.datasets.graph_generator import GraphGenerator
  from torch_geometric.utils import erdos_renyi_graph
label_desc: Use image node_id 2 for calling the ERGraph obj's underlying member method code with example usage: obj.__call__() and returns: Data