Create thread

{
  "comment": "string",
  "customer_external_ids": [
    "string"
  ],
  "customer_ids": [
    "string"
  ],
  "reminder": {
    "delay": "integer",
    "number_left": "integer"
  },
  "status": "integer",
  "tag_codes": [
    "string"
  ]
}

{
  "attachments": [
    {
      "attachment_movements": {
        "movements": [
          {
            "agent_id": "integer",
            "customer_id": "string",
            "file_id": "string"
          }
        ],
        "total": "integer"
      },
      "file_mime": "string",
      "file_name": "string",
      "file_not_dangerous": "boolean",
      "file_size": "integer",
      "file_type": "string",
      "id": "string"
    }
  ],
  "client_id": "integer",
  "contacts": [
    "string"
  ],
  "created_at": "string",
  "customers": [
    {
      "account_number": "string",
      "account_type": {},
      "alias_ids": [
        "string"
      ],
      "client_id": "string",
      "comment": "string",
      "company_name": "string",
      "contacts": "string",
      "created_at": "string",
      "created_by": "integer",
      "custom_fields": "object",
      "customer_type": "string",
      "date_of_birth": "string",
      "disabled": "boolean",
      "domicile_code": "string",
      "domicile_codes": [
        "string"
      ],
      "external_id": "string",
      "first_name": "string",
      "id": "string",
      "kyc_level": "integer",
      "last_name": "string",
      "middle_name": "string",
      "name_variations": [
        {
          "company_name": "string",
          "first_name": "string",
          "last_name": "string",
          "middle_name": "string",
          "trading_name": "string"
        }
      ],
      "nationality_code": "string",
      "nationality_codes": [
        "string"
      ],
      "phone": "string",
      "registration_number": "string",
      "review_groups": [
        "string"
      ],
      "revision_number": "string",
      "trading_name": "string"
    }
  ],
  "external_message_ids": [
    "string"
  ],
  "id": "string",
  "last_message": {
    "agent_id": "integer",
    "attachments": [
      {
        "attachment_movements": {
          "movements": [
            {
              "agent_id": "integer",
              "customer_id": "string",
              "file_id": "string"
            }
          ],
          "total": "integer"
        },
        "file_mime": "string",
        "file_name": "string",
        "file_not_dangerous": "boolean",
        "file_size": "integer",
        "file_type": "string",
        "id": "string"
      }
    ],
    "bcc": "string",
    "cc": "string",
    "content": "string",
    "created_at": "string",
    "delivery": {},
    "error_when_trying_to_send": "string",
    "external_message_id": "string",
    "from": "string",
    "id": "string",
    "mailbox_id": "string",
    "origin": {},
    "priority": "integer",
    "raw_message": "string",
    "read_by_agents": [
      "integer"
    ],
    "reply_to_external_message_id": "string",
    "subject": "string",
    "to": "string"
  },
  "message_count": "integer",
  "reminder": {
    "delay": "integer",
    "next_date": "string",
    "number_left": "integer"
  },
  "review_groups": [
    "string"
  ],
  "status": {},
  "tags": [
    "string"
  ],
  "updated_at": "string"
}