Function order_statement_ctes 

pub fn order_statement_ctes<'a>(
    ctes: &'a [CtePlan],
    scheduled: Vec<&'a CtePlan>,
    primary_references: &BTreeSet<String>,
) -> StatementCteOrder<'a>

Split scheduled, the items of ctes that a statement materializes in dependency order, into the items that run before its primary query and the items that run after it. primary_references names the items the primary query reads.