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When a MultiSelect is instatiated with in a hidden parent element, the calculation to size the label to avoid the dropdown icon is incorrect.
See the repro here: https://codesandbox.io/s/focused-morse-5l7nb
(note that the larger size of the .e-searcher element forces the label to sit above its anticipated position).
The problem code is in: multi-select.js (MultiSelect.prototype.checkPlaceholderSize)