static filterOut(arr, excludedElements) {
        return arr.filter(element => !this.isInArray(element, excludedElements));
    }
Filter out the given `arr` array with the elements found in `excludedElements`.
This returns a new array and does not modify the source.
cf. verification here : http://codepen.io/AnotherLinuxUser/pen/XpvrMg?editors=0012

@param {Array} arr
@param {Array} excludedElements
@returns {*|Array.<T>}