Either you can ignore the warning or you can create an identical local array, copy all values over then return the new array. You only want to do it if you really want to restrict user from manipulating your array (internal state) indirectly (i.e. not via your object method, but to get the array, and manipulate its values hence your internal array changes accordingly).
“Everything should be as simple as it is, but not simpler.” Albert Einstein
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