Crash if trying to save without touching the canvas?
So If I call save without drawing anything I get a crash

~~~
default	15:33:58.172747 +0100	paack	Exception '*** -[_NSPlaceholderData initWithBase64EncodedString:options:]: nil string argument' was thrown while invoking saveDrawing on target RNSketchManager with params (
    "<null>",
    png,
    2618,
    2619
)
callstack: (
	0   CoreFoundation                      0x00000001058421ab __exceptionPreprocess + 171
	1   libobjc.A.dylib                     0x0000000103d3cf41 objc_exception_throw + 48
	2   CoreFoundation                      0x00000001058b6cb5 +[NSException raise:format:] + 197
	3   Foundation                          0x00000001037612bb -[NSData(NSData) initWithBase64EncodedString:options:] + 84
	4   paack                               0x000000010323651a -[RNSketchManager saveDrawing:ofType:resolve:reject:] + 538
	5   CoreFoundation                      0x00000001057c649c __invoking___ + 140
	6   CoreFoundation                      0x00000001057c6370 -[NSInvocation invoke] + 320
	7   CoreFoundation                      0x00000001057ded56 -[NSInvocation invokeWithTarget:] + 54
	8   pa<…>

~~~

Thank you 😊