Unihiker K10, Capture camera image, Micropython

Hi, 

I try to use the camera.capture() function on the K10 board in Micropython. I found this function via help(camera) to get all available function. 

I was hoping to get a filled Framebuffer to send a picture via email.

But calling this: 

camera.init()

buffer = camera.capture()

Leads to this error:

Traceback (most recent call last):
 File "k10_base/_k10_base.py", line 155, in func
 File "main.py", line 35, in button_a_pressed
 File "main.py", line 61, in take_and_send_photo
NameError: name 'Len' isn't defined

Any ideas ? Thank you !