Assigns own and inherited enumerable string keyed properties of source
objects to the destination object for all destination properties that
resolve to undefined. Source objects are applied from left to right.
Once a property is set, additional values of the same property are ignored.
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to
undefined
. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored.Note: This method mutates
object
.