removeCircular bug

[kentcdodds]

This:

{
  "ivrComponents": [
    {
      "id": "n-start",
      "left": "29px",
      "top": "19px",
      "type": "INCOMING"
    },
    {
      "type": "HANGUP",
      "id": "n-HANGUP-2",
      "top": "96px",
      "left": "928px"
    },
    {
      "type": "SCHEDULE",
      "id": "n-SCHEDULE-3",
      "catchAllRule": {
        "id": "n-SCHEDULE-3-rule-0",
        "name": "All other times/days",
        "type": "SCHEDULE_RULE_COMPONENT",
        "ruleType": "CATCH_ALL"
      },
      "scheduleComponent": [
        {
          "id": "n-SCHEDULE-3-rule-0",
          "name": "All other times/days",
          "type": "SCHEDULE_RULE_COMPONENT",
          "ruleType": "CATCH_ALL"
        }
      ],
      "top": "33px",
      "left": "434px"
    }
  ],
  "name": "ivrnpe",
  "ivrComponentMappings": [
    {
      "fromIvrComponentId": "n-start",
      "toIvrComponentId": "n-SCHEDULE-3"
    },
    {
      "fromIvrComponentId": "n-SCHEDULE-3-rule-0",
      "toIvrComponentId": "n-HANGUP-2"
    }
  ]
}

Is getting transformed into this:

{
  "ivrComponents": [
    {
      "id": "n-start",
      "left": "29px",
      "top": "19px",
      "type": "INCOMING"
    },
    {
      "type": "HANGUP",
      "id": "n-HANGUP-2",
      "top": "96px",
      "left": "928px"
    },
    {
      "type": "SCHEDULE",
      "id": "n-SCHEDULE-3",
      "catchAllRule": {
        "id": "n-SCHEDULE-3-rule-0",
        "name": "All other times/days",
        "type": "SCHEDULE_RULE_COMPONENT",
        "ruleType": "CATCH_ALL"
      },
      "scheduleComponent": [
        null // <------------------------------------- that's the problem!!!!!!!!
      ],
      "top": "33px",
      "left": "434px"
    }
  ],
  "name": "ivrnpe",
  "ivrComponentMappings": [
    {
      "fromIvrComponentId": "n-start",
      "toIvrComponentId": "n-SCHEDULE-3"
    },
    {
      "fromIvrComponentId": "n-SCHEDULE-3-rule-0",
      "toIvrComponentId": "n-HANGUP-2"
    }
  ]
}

The null should be the value it was before. The same object is in the catchAllRule, but it's not circular (I can JSON.stringify).

Thanks!