function hasOverlap(array1, array2) {
      for (var i = 0; i < array1.length; i++) {
        if (contains(array2, array1[i])) {
          return true;
        }
      }

      return false;
    }
Test whether two arrays have overlapping items
@param {Array} array1
@param {Array} array2
@return {boolean} Returns true when at least one item exists in both arrays