code: def _get_causal_model_from_eq():
      causal_model = create_causal_model_from_equations(
          """
      X0 = norm(loc=0,scale=0.1)
      X1 = 2*X0 + norm(loc=0, scale=0.1)
      X2 = 0.5*X0 + norm(loc=0, scale=0.1)
      X3 = 0.5*X2 + norm(loc=0, scale=0.1)
      """
      )
      return causal_model
  
file_path: dowhy/tests/gcm/test_equation_parser.py
imports: import networkx
  import numpy
  import pandas
  from flaky import flaky
  from dowhy.gcm import AdditiveNoiseModel, EmpiricalDistribution, ProbabilisticCausalModel, create_causal_model_from_equations, fit
  from dowhy.gcm.causal_mechanisms import ConditionalStochasticModel
  from dowhy.gcm.ml import create_linear_regressor_with_given_parameters
label_desc: Use image node_id 6 for calling a global function with example usage: _get_causal_model_from_eq() and returns: causal_model