Get the last element of an array. Passing **n** will return the last N
        values in the array.
        The **guard** check allows it to work with `_.map`.

def last(self, n=1):
        """
        Get the last element of an array. Passing **n** will return the last N
        values in the array.
        The **guard** check allows it to work with `_.map`.
        """
        res = self.obj[-n:]
        if len(res) is 1:
            res = res[0]
        return self._wrap(res)