code: def simple_linear_outcome_model(X_train, output_train):
      # The outcome is a linear function of the confounder
      # The slope is 1,2 and the intercept is 3
      return lambda X_train: X_train[:, 0] + 2 * X_train[:, 1] + 3
  
imports: from pytest import mark
  from .base import SimpleRefuter
label_desc: Use image node_id 1 for calling a global function with example usage: simple_linear_outcome_model(X_train, output_train) and returns: function