Function anchor 

pub fn anchor(
    place: &str,
    clocks: &str,
    setup: &str,
    instance: &str,
) -> Result<Anchor, AnchorError>

The anchor of instance from a fitted build’s reports: the clock its setup paths run on (instance_clock), that clock’s targets in the clock table, and the fast signal of the place report those targets come from (clock_site).