Part returns the route part on the desired position. The Route gets validated before extracting the part. Does not run Validate() Have Route: general/single_store_mode/enabled Pos<1 => ErrIncorrectPosition Pos=1 => general Pos=2 => single_store_mode Pos=3 => enabled Pos>3 => ErrIncorrect
(pos int)
source not stored for this graph (policy: none)