class_docstr: A simple linear regression model used for testing.
class_docstr_tok: ["A","simple","linear","regression","model","used","for","testing","."]
code: def initialize_metadata(self) -> None:
      self.__num_features: Optional[int] = None
  
imports: import numpy
  import torch
  from torch import nn
  from typing import Any, Dict, Iterator, NamedTuple, Optional, Union
  from ptgnn.baseneuralmodel import AbstractNeuralModel, ModuleWithMetrics
  from ptgnn.baseneuralmodel.utils.data import enforce_not_None
  from ptgnn.tests.simplemodel.data import SampleDatapoint
label_desc: Use image node_id 1 for calling the SimpleRegressionModel obj's underlying member method code with example usage: obj.initialize_metadata() without return types