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    "## Constraints and Assumptions\n",
    "> Can we assume the list fits in memory?\n",
    "\n",
    "Yes\n",
    "\n",
    "> Do we have to worry about load factors?\n",
    "\n",
    "No\n",
    "\n",
    "> Can we assume inputs are valid or do we have to validate them?\n",
    "\n",
    "Assume they are valid"
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    "class CircularArray:\n",
    "    \"\"\"\n",
    "    Python class implementing a circular array.\n",
    "    \"\"\"\n",
    "    def __init__(self, size):\n",
    "        \"\"\"\n",
    "        Constructor. Refer to `full()` for explanation for `size+1`.\n",
    "        \"\"\"\n",
    "        self._size = size + 1\n",
    "        self._items = [None for _ in range(self._size)]\n",
    "        self._read = 0    # read pointer\n",
    "        self._write = 0   # write pointer\n",
    "        \n",
    "    @property\n",
    "    def empty(self):\n",
    "        \"\"\"\n",
    "        Returns whether the queue is empty.\n",
    "        \"\"\"\n",
    "        return self._read == self._write\n",
    "    \n",
    "    @property\n",
    "    def full(self):\n",
    "        \"\"\"\n",
    "        Return wheter the queue is full.\n",
    "        In a naive implementation, full and empty are both indicated by read == write, which introduces an\n",
    "        ambiguity. Thus, to break this, a circular array is assumed to be full if the write pointer is one\n",
    "        position behind the read pointer. To preserve the inituitiveness of the class interface, the internal\n",
    "        size property is incremented by 1, a sentinel element (so this way the user won't be surprised that their\n",
    "        array that supposedly fits 10 elements only accomodates 9).\n",
    "        \"\"\"\n",
    "        return self._read == (self._write + 1) % self._size\n",
    "    \n",
    "    def queue(self, item):\n",
    "        \"\"\"\n",
    "        Enqueues an item in the circular buffer.\n",
    "        \"\"\"\n",
    "        if self.full:\n",
    "            raise BufferError('Queue is full')\n",
    "        self._items[self._write] = item\n",
    "        self._write = (self._write + 1) % self._size\n",
    "    \n",
    "    def dequeue(self):\n",
    "        \"\"\"\n",
    "        Dequeues an item from the buffer.\n",
    "        \"\"\"\n",
    "        if self.empty:\n",
    "            raise BufferError('Queue is empty')\n",
    "        item = self._items[self._read]\n",
    "        self._items[self._read] = None\n",
    "        self._read = (self._read + 1) % self._size\n",
    "        return item"
   ]
  }
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