code: def test_formula_repr():
      f1 = bmb.Formula("y ~ x")
      f2 = bmb.Formula("y ~ x", "sigma ~ 1", "gamma ~ x")
  
      assert repr(f1) == "Formula('y ~ x')"
      assert repr(f2) == "Formula('y ~ x', 'sigma ~ 1', 'gamma ~ x')"
  
file_path: bambi/tests/test_formula.py
imports: import pytest
  import bambi
label_desc: Use image node_id 6 for calling a global function with example usage: test_formula_repr() without return types