Creates an execution order that trades the given parent order with the firm's own inventory, booked to the principal account (book) in principal_account_id. No venue is involved: the execution order fills at price for amount.

Requirements:

• The parent order must be all-or-none, in the pending_execution state, with no live or filled execution order.
• The execution order must cover the whole order.
• Bonds only: amount must be par, and price is percent of par.
• Either side: a buy sells to the client from the book, a sell buys from the client into the book.

Once submitted, you will receive one of the following events:

• A system_update event with an event_type of execution_order_request that indicates the request was received.
• A system_update event with an event_type of execution_order_reject if the request fails.
• An order_update event with an event_type of execution_order_create if the request succeeds.

All events include the execution_order_id.