Function index_only_serialization_refusal 

pub fn index_only_serialization_refusal(
    error: &ProtocolError,
) -> Option<QuerySyntaxError>

The query error a failure serializing a document an indexOnly index synthesized answers a non-proof read with, None when the failure is no query’s doing: a missing required property, which DriveDocumentQuery::refuse_an_uncovered_index_only_projection refuses before the read, so this only guards a read that check let through. The documents query and drive-abci’s chained and composite handlers share it.