---
Hash (size=1 message='My circular hashes'):
  Pair 0:
    Key:
      Symbol (size=3):
        to_s: foo
        encoding: !ruby/encoding US-ASCII
    Value:
      Hash (size=1):
        Pair 0:
          Key:
            Symbol (size=3):
              to_s: bar
              encoding: !ruby/encoding US-ASCII
          Value: Hash {:foo=>{:bar=>{...}}}