Function parseWebhookEvent

parseWebhookEvent(
headers: WebhookHeadersInput | undefined,
body: unknown,
): BitbucketWebhookEvent
Parses an incoming Bitbucket Data Center webhook delivery into a typed, discriminated BitbucketWebhookEvent, detecting the event type from the X-Event-Key header (falling back to the body's eventKey field, which Bitbucket includes on every event except diagnostics:ping).

This performs no signature verification and no runtime schema validation — body is trusted as-is (cast to the shape implied by the event key), matching how the rest of this client trusts JSON response bodies. Verify your webhook's shared secret yourself if you configured one.
Parameters
- headers: WebhookHeadersInput | undefined
  The incoming request's headers (any WebhookHeadersInput)
- body: unknown
  The already-JSON-parsed request body
Returns BitbucketWebhookEvent
Throws
If no event key can be determined from either the headers or the body
Example
```
import { parseWebhookEvent } from 'bitbucket-datacenter-api-client';

app.post('/webhooks/bitbucket', (req, res) => {
  const { event, payload } = parseWebhookEvent(req.headers, req.body);

  switch (event) {
    case 'pr:opened':
      console.log('New PR:', payload.pullRequest.title);
      break;
    case 'repo:refs_changed':
      console.log('Pushed refs:', payload.changes.map((c) => c.ref.displayId));
      break;
    default:
      console.log('Unhandled event:', event);
  }

  res.sendStatus(204);
});
```
- Defined in src/webhooks.ts:112