code: def __init__(self, input_dim=16, output_dim=3, noise_level=1e-5):
      self._input_dim = input_dim
      self._output_dim = output_dim
      self._noise_level = noise_level
      self._matrix_gen_seed = 0
      self._generate_matrices()
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import pytest
  import numpy
  import torch
  import torch.nn
  import torch.optim
  from torch.utils.data import Dataset, DataLoader
  import bluefog.torch
  from bluefog.common import topology_util
label_desc: Use image node_id 1 to create a new LinearProblemBuilder object  with example: obj = LinearProblemBuilder(input_dim, output_dim, noise_level)