class UniqueInOrderIterator:
    def __init__(self, iterable):
        self.__iterable = iterable
        self.__currentPosition = 0
        self.__lastElement = None
    
    def __iter__(self):
        return self
    
    def __next__(self):
        self.__pointToNextValidElement()
        result = self.__pointedElement()
        self.__pointToNextElement()
        return result
    
    def __pointToNextValidElement(self):
        while (self.__currentPosition < len(self.__iterable)
                and self.__iterable[self.__currentPosition] == self.__lastElement):
            self.__pointToNextElement()
    
    def __pointedElement(self):
        return self.__iterable[self.__currentPosition]
    
    def __pointToNextElement(self):
        self.__lastElement = self.__pointedElement()
        self.__currentPosition += 1
        self.__stopIfEndReached()
    
    def __stopIfEndReached(self):
        if self.__currentPosition >= len(self.__iterable):
            raise StopIteration
    
            

def unique_in_order(iterable):
    unique = []
    uniqueInOrderIterator = UniqueInOrderIterator(iterable)
    
    for element in uniqueInOrderIterator:
        unique.append(element)

    return unique

class UniqueInOrderIterator:
    def __init__(self, iterable):
        self.__iterable = iterable
        self.__currentPosition = 0
        self.__lastElement = None
    
    def __iter__(self):
        return self
    
    def __next__(self):
        self.__pointToNextValidElement()
        result = self.__pointedElement()
        self.__pointToNextElement()
        return result
    
    def __pointToNextValidElement(self):
        while (self.__currentPosition < len(self.__iterable)
                and self.__iterable[self.__currentPosition] == self.__lastElement):
            self.__pointToNextElement()
    
    def __pointedElement(self):
        return self.__iterable[self.__currentPosition]
    
    def __pointToNextElement(self):
        self.__lastElement = self.__pointedElement()
        self.__currentPosition += 1
        self.__stopIfEndReached()
    
    def __stopIfEndReached(self):
        if self.__currentPosition >= len(self.__iterable):
            raise StopIteration
    
            

def unique_in_order(iterable):
    unique = []
    uniqueInOrderIterator = UniqueInOrderIterator(iterable)
    
    for element in uniqueInOrderIterator:
        unique.append(element)

    return unique

def unique_in_order(iterable):
    unique = []
    
    for i in range(len(iterable)):
        if (i == 0):
            unique.append(iterable[i])
        elif iterable[i] != unique[-1]:
            unique.append(iterable[i])

    return unique