This is a utility function that does a shallow copy of properties from one object to another. It is used inside
and exposed because it is frequently required by user’s code.
It copies properties from one object to another. The copy is shallow and does not involve cloning of objects.
The best way to describe
dcl.mix() is to give its definition:
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Even for totally empty objects IE6 lists some internal methods. Usually copying of these methods does no harm to objects.