Implement the Queue ADT using circular array approach and test it using assert statements. CircularQueue.py contains skeleton code with a DEFAULT_CAPACITY = 10

class CircularQueue:

DEFAULT_CAPACITY = 10

def __init__(self):

""" Creating an empty queue. """

self._data = [None] * self.DEFAULT_CAPACITY

self._size = 0

self._front = 0

def __len__(self):

pass

def is_empty(self):

pass

def first(self):

""" Return (but do not remove) the first element of the queue. """

pass

def dequeue(self):

" Remove and return the first element of the queue. (FIFO)"

pass

def enqueue(self, e):

pass