Update draft

{
  "type": "object",
  "properties": {
    "draftId": {
      "type": "string",
      "minLength": 1
    },
    "accountId": {
      "anyOf": [
        {
          "type": "string",
          "minLength": 1
        },
        {
          "type": "null"
        }
      ],
      "description": "Account to operate on. Optional when exactly one account is connected."
    },
    "from": {
      "anyOf": [
        {
          "type": "string",
          "format": "email"
        },
        {
          "type": "null"
        }
      ],
      "description": "Connected address or an available send-as address"
    },
    "to": {
      "anyOf": [
        {
          "type": "array",
          "items": {
            "type": "string",
            "minLength": 1
          },
          "description": "Recipients, each \"Name <a@x.com>\" or \"a@x.com\""
        },
        {
          "type": "null"
        }
      ],
      "description": "Recipients, each \"Name <a@x.com>\" or \"a@x.com\""
    },
    "cc": {
      "anyOf": [
        {
          "$ref": "#/properties/to/anyOf/0"
        },
        {
          "type": "null"
        }
      ],
      "description": "Recipients, each \"Name <a@x.com>\" or \"a@x.com\""
    },
    "bcc": {
      "anyOf": [
        {
          "$ref": "#/properties/to/anyOf/0"
        },
        {
          "type": "null"
        }
      ],
      "description": "Recipients, each \"Name <a@x.com>\" or \"a@x.com\""
    },
    "subject": {
      "type": [
        "string",
        "null"
      ],
      "description": "Defaults to \"Re: ...\" when replying"
    },
    "bodyText": {
      "type": [
        "string",
        "null"
      ],
      "description": "Plain-text body. Line breaks appear in the sent email. Keep each prose paragraph on one continuous line and separate paragraphs with blank lines."
    },
    "bodyHtml": {
      "type": [
        "string",
        "null"
      ],
      "description": "HTML body"
    },
    "replyToMessageId": {
      "anyOf": [
        {
          "$ref": "#/properties/draftId"
        },
        {
          "type": "null"
        }
      ],
      "description": "Message being replied to; threads correctly and computes recipients if \"to\" is omitted"
    },
    "replyAll": {
      "type": [
        "boolean",
        "null"
      ],
      "description": "With replyToMessageId: reply to all original recipients"
    },
    "attachments": {
      "anyOf": [
        {
          "type": "array",
          "items": {
            "type": "object",
            "properties": {
              "filename": {
                "type": "string",
                "minLength": 1
              },
              "mimeType": {
                "type": "string",
                "minLength": 1
              },
              "content": {
                "type": "string",
                "description": "base64"
              }
            },
            "required": [
              "filename",
              "mimeType",
              "content"
            ],
            "additionalProperties": false
          }
        },
        {
          "type": "null"
        }
      ]
    }
  },
  "required": [
    "draftId"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}