class_docstr: Dummy step that takes multiple inputs and produces a single output.
class_docstr_tok: ["Dummy","step","that","takes","multiple","inputs","and","produces","a","single","output","."]
code: def fit(self, Xs, ys):
      # Suppose that this dummy model expects two inputs and two targets
      self.fitted_ = True
      return self
  
imports: from sklearn.base import BaseEstimator
  from baikal import Step, make_step
label_desc: Use image node_id 3 for calling the DummyMISO obj's underlying member method code with example usage: obj.fit(Xs, ys) and returns: self