asynctypes-685526: Implement getBlank() directly
asynctypes-685526: Implement getBlank() directly

We're making parse asynchronous, and getBlank is synchronous so we need
to implement it directly rather than using parse().

Signed-off-by: Joe Walker <7a17872fbb32c7d760c9a16ee3076daead11efcf@mozilla.com>

joewalker/gcli,joewalker/gcli,mozilla/gcli,mozilla/gcli,mozilla/gcli