default value. It is used when FGHJ value equals Fghj.init.
cast(T) this if this != Fghj.init and def otherwise.
import fghj.jsonparser; auto fghjData = `{"foo":"bar","inner":{"a":true,"b":false,"c":"32323","d":null,"e":{}}}`.parseJson; assert(fghjData["inner", "a"].get(false) == true); assert(fghjData["inner", "b"].get(true) == false); assert(fghjData["inner", "c"].get(100) == 32323); assert(fghjData["no", "such", "keys"].get(100) == 100);