Function complete_bpmn_user_task 

pub async fn complete_bpmn_user_task(
    configuration: &Configuration,
    workspace: &str,
    id: &str,
    user_task_id: &str,
    request_body: HashMap<String, Value>,
) -> Result<String, Error<CompleteBpmnUserTaskError>>

Deliver a user task’s form data and unpark the instance. The body is the completion payload; when the task declares form fields it is validated against them server-side (required fields, declared defaults, enum values – see #833), unless the model sets flowable:formFieldValidation=\"false\". Since #1104 the caller must be in the task’s declared audience. This was previously unenforced: anyone who could see an instance could complete any of its user tasks, including one assigned to somebody else.