Attaches a descriptor to a message without adding an enumerable property.
The function normally changes and returns message. If the object does not
accept a new property, it creates a shallow copy, attaches the descriptor,
and returns that copy. Always use the returned value.
If descriptor is absent, the function returns message unchanged.
Attaches a descriptor to a message without adding an enumerable property.
The function normally changes and returns
message. If the object does not accept a new property, it creates a shallow copy, attaches the descriptor, and returns that copy. Always use the returned value.If
descriptoris absent, the function returnsmessageunchanged.