The type that you use in a generic declaration can be nullable. Here, we are declaring a MutableList of String?, so we can put null values in the list.

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Nullable Generic Types Nullable Generic Types, Continued
Elvis Returns! Functions on Nullable Types Nullable Casts Nullable Casts, Continued Nullable Generic Types Nullable Generic Types, Continued Nullable Types Safe Call Chains Safe Calls Smart Contracts The Elvis Operator
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