pub fn merge(
model: &mut [ValidatedField],
fallback: &[FallbackField],
fill: Fill,
request_produced_output: bool,
) -> BTreeMap<String, Vec<String>>Expand description
Merge by field name, preserving model order and every present model field.
request_produced_output distinguishes an accepted record with absent fields
from a request failure. The caller supplies model entries for the full schema.
Returns source lineage only for fallback entries actually selected by the fill.