function isEqual(value, other, customizer, thisArg) {
	      customizer = typeof customizer == 'function' ? bindCallback(customizer, thisArg, 3) : undefined;
	      var result = customizer ? customizer(value, other) : undefined;
	      return  result === undefined ? baseIsEqual(value, other, customizer) : !!result;
	    }
Performs a deep comparison between two values to determine if they are
equivalent. If `customizer` is provided it is invoked to compare values.
If `customizer` returns `undefined` comparisons are handled by the method
instead. The `customizer` is bound to `thisArg` and invoked with three
arguments: (value, other [, index|key]).

**Note:** This method supports comparing arrays, booleans, `Date` objects,
numbers, `Object` objects, regexes, and strings. Objects are compared by
their own, not inherited, enumerable properties. Functions and DOM nodes
are **not** supported. Provide a customizer function to extend support
for comparing other values.

@static
@memberOf _
@alias eq
@category Lang
@param {*} value The value to compare.
@param {*} other The other value to compare.
@param {Function} [customizer] The function to customize value comparisons.
@param {*} [thisArg] The `this` binding of `customizer`.
@returns {boolean} Returns `true` if the values are equivalent, else `false`.
@example

var object = { 'user': 'fred' };
var other = { 'user': 'fred' };

object == other;
// => false

_.isEqual(object, other);
// => true

// using a customizer callback
var array = ['hello', 'goodbye'];
var other = ['hi', 'goodbye'];

_.isEqual(array, other, function(value, other) {
  if (_.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/)) {
    return true;
  }
});
// => true