Function datafusion_physical_expr::utils::normalize_ordering_equivalence_classes

pub fn normalize_ordering_equivalence_classes(
    oeq_classes: &[OrderingEquivalentClass],
    eq_properties: &EquivalenceProperties
) -> Vec<OrderingEquivalentClass>

This function normalizes oeq_classes expressions according to eq_properties. More explicitly, it makes sure that expressions in oeq_classes are head entries in eq_properties, replacing any non-head entries with head entries if necessary.