ts
export class TransferPlan {
  /**
   * This configures how transfer is executed and the experience of the destination party receiving the call.
   *
   * Usage:
   * - `blind-transfer`: The assistant forwards the call to the destination without any message or summary.
   * - `blind-transfer-add-summary-to-sip-header`: The assistant forwards the call to the destination and adds a SIP header X-Transfer-Summary to the call to include the summary.
   * - `warm-transfer-say-message`: The assistant dials the destination, delivers the `message` to the destination party, connects the customer, and leaves the call.
   * - `warm-transfer-say-summary`: The assistant dials the destination, provides a summary of the call to the destination party, connects the customer, and leaves the call.
   * - `warm-transfer-wait-for-operator-to-speak-first-and-then-say-message`: The assistant dials the destination, waits for the operator to speak, delivers the `message` to the destination party, and then connects the customer.
   * - `warm-transfer-wait-for-operator-to-speak-first-and-then-say-summary`: The assistant dials the destination, waits for the operator to speak, provides a summary of the call to the destination party, and then connects the customer.
   * - `warm-transfer-twiml`: The assistant dials the destination, executes the twiml instructions on the destination call leg, connects the customer, and leaves the call.
   *
   * @default 'blind-transfer'
   */
  mode: TransferMode;

  /**
   * This is the message the assistant will deliver to the destination party before connecting the customer.
   *
   * Usage:
   * - Used only when `mode` is `blind-transfer-add-summary-to-sip-header`, `warm-transfer-say-message` or `warm-transfer-wait-for-operator-to-speak-first-and-then-say-message`.
   */
  message?: string | Message;


  /**
   * This is the plan for generating a summary of the call to present to the destination party.
   *
   * Usage:
   * - Used only when `mode` is `blind-transfer-add-summary-to-sip-header` or `warm-transfer-say-summary` or `warm-transfer-wait-for-operator-to-speak-first-and-then-say-summary`.
   */
  summaryPlan?: SummaryPlan;

  /**
   * This specifies the SIP verb to use while transferring the call.
   * - 'refer': Uses SIP REFER to transfer the call (default)
   * - 'bye': Ends current call with SIP BYE
   */
  sipVerb?: 'refer' | 'bye' = 'refer';

  /**
   * This is the TwiML instructions to execute on the destination call leg before connecting the customer.
   *
   * Usage:
   * - Used only when `mode` is `warm-transfer-twiml`.
   * - Supports only `Play`, `Say`, `Gather`, `Hangup` and `Pause` verbs.
   * - Maximum length is 4096 characters.
   *
   * Example:
   * 
       * <Say voice="alice" language="en-US">Hello, transferring a customer to you.</Say>
       * <Pause length="2"/>
       * <Say>They called about billing questions.</Say>
       * 
 */
  @MaxLength(4096)
  twiml?: string;
}