(self, seq)
return first, chain([first], seq)
Args:
            seq: an iterator.

        Returns:
            the first thing returned by calling next() on the iterator
            and an iterator created by re-chaining that value to the beginning
            of the iterator.
Args:
            seq: an iterator.
Args : seq : an iterator .
def _peek(self, seq):
        """
        Args:
            seq: an iterator.

        Returns:
            the first thing returned by calling next() on the iterator
            and an iterator created by re-chaining that value to the beginning
            of the iterator.
        """
        first = next(seq)
        return first, chain([first], seq)
def _peek ( self , seq ) : first = next ( seq ) return first , chain ( [ first ] , seq )