Function mz_sql::plan::query::handle_mutation_using_clause

fn handle_mutation_using_clause(
    qcx: &QueryContext<'_>,
    selection: Option<Expr<Aug>>,
    using: Vec<TableWithJoins<Aug>>,
    get: HirRelationExpr,
    outer_scope: Scope
) -> Result<HirRelationExpr, PlanError>