How would look get component in Boo

i try to use

o.GetComponent<Image>().sprite = mysprite

to assign a sprite to my prefab gameobject.
However i use Python.
Since Boo is similar to python i would like to get the right syntax for that.
Python does complain about the < > operator which means something completely different in python.

For more info

(click the Boo button to see syntax)