How do I output information in pre-request script

Using the standalone version of Postman, how do I output some debug information in Postman pre-request script?

The code below works great for tests (post-request) but not for pre-request since there is no tests[] array.

var jsonData = JSON.parse(responseBody);
tests["key = " + jsonData.key] = true;              // debug message
tests["value = " + jsonData.value] = true;          // debug message