presto-mongodb/src/main/java/io/prestosql/plugin/mongodb/MongoPageSink.java/MongoPageSink/isImplicitRowType
class MongoPageSink:    private boolean isImplicitRowType(Type type)
    {
        return type.getTypeSignature().getParameters()
                .stream()
                .map(TypeSignatureParameter::getNamedTypeSignature)
                .map(NamedTypeSignature::getName)
                .filter(Optional::isPresent)
                .map(Optional::get)
                .allMatch(name -> name.startsWith(implicitPrefix));
    }