Function allows 

pub fn allows(shim: &dyn Shim, op: &Op, g: &TensorGraph) -> Allow

Whether the chip runs op: a fused op of a class it links whole that its link builds as it stands (Native), one of a class it runs as its parts, every part allowed (Decompose), or neither, by name — a refused part names the part and its own reason. A lifted op, a view or a quantize is judged by its shape alone.