pub fn take_over_root(
c: &mut Client,
me: &str,
root: &str,
old: &str,
) -> Result<Vec<(String, i64)>, Error>Expand description
Take over one execution tree from old: every execution of root that
old owns moves to me with its epoch incremented. Concurrent callers
each win a disjoint set of rows (the update re-checks node_id = old
after waiting for a competing update). Returns (execution, new epoch).