Creates a duplicate-value-free version of an array using strict equality
for comparisons, i.e. `===`. If the array is sorted, providing
`true` for `isSorted` will use a faster algorithm. If a callback is provided
each element of `array` is passed through the callback before uniqueness
is computed. The callback is bound to `thisArg` and invoked with three
arguments; (value, index, array).

If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.

If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.

@static
@memberOf _
@alias unique
@category Arrays
@param {Array} array The array to process.
@param {boolean} [isSorted=false] A flag to indicate that `array` is sorted.
@param {Function|Object|string} [callback=identity] The function called
per iteration. If a property name or object is provided it will be used
to create a "_.pluck" or "_.where" style callback, respectively.
@param {*} [thisArg] The `this` binding of `callback`.
@returns {Array} Returns a duplicate-value-free array.
@example

_.uniq([1, 2, 1, 3, 1]);
// => [1, 2, 3]

_.uniq([1, 1, 2, 2, 3], true);
// => [1, 2, 3]

_.uniq(['A', 'b', 'C', 'a', 'B', 'c'], function(letter) { return letter.toLowerCase(); });
// => ['A', 'b', 'C']

_.uniq([1, 2.5, 3, 1.5, 2, 3.5], function(num) { return this.floor(num); }, Math);
// => [1, 2.5, 3]

// using "_.pluck" callback shorthand
_.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]
function uniq(array, isSorted, callback, thisArg) {
      // juggle arguments
      if (typeof isSorted != 'boolean' && isSorted != null) {
        thisArg = callback;
        callback = !(thisArg && thisArg[isSorted] === array) ? isSorted : null;
        isSorted = false;
      }
      if (callback != null) {
        callback = lodash.createCallback(callback, thisArg, 3);
      }
      return baseUniq(array, isSorted, callback);
    }