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METHODS NOT PART OF THE `Set` spec for ES6:
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Adds item onto `SjlSet` from the passed in array.
@method sjl.stdlib.SjlSet#addFromArray
@param value {Array}
@returns {sjl.stdlib.SjlSet}
function (value) {
            // Iterate through the passed in iterable and add all values to `_values`
            var iterator = makeIterable(value, 0)[sjl.Symbol.iterator]();

            // Loop through values and add them
            while (iterator.valid()) {
                this.add(iterator.next().value);
            }
            iterator = null;
            return this;
        }