code: def test_hash_rule():
      assert_equal(len({Rule("a <= 2 and a <= 3"), Rule("a <= 2")}), 1)
      assert_not_equal(
          len({Rule("a <= 4 and a <= 3"), Rule("a <= 2")}), 1
      )
  
imports: from sklearn.utils.testing import assert_equal, assert_not_equal
  from skrules import Rule, replace_feature_name
label_desc: Use image node_id 2 for calling a global function with example usage: test_hash_rule() without return types