in bigquery/src/main/scala/magnolify/bigquery/TableRowType.scala [145:153]
override def from(v: ju.Map[String, AnyRef])(cm: CaseMapper): T =
caseClass.construct { p =>
val f = v.get(cm.map(p.label))
if (f == null && p.default.isDefined) {
p.default.get
} else {
p.typeclass.fromAny(f)(cm)
}
}