Traceback (most recent call last):
  File "JPEG.py", line 371, in <module>
    img.decode()
  File "JPEG.py", line 353, in decode
    len_chunk = self.StartOfScan(data, len_chunk)
  File "JPEG.py", line 284, in StartOfScan
    st, 0, self.quant[self.quantMapping[0]], oldlumdccoeff
  File "JPEG.py", line 247, in BuildMatrix
    code = self.huffman_tables[0 + idx].GetCode(st)
  File "JPEG.py", line 192, in GetCode
    res = self.Find(st)
  File "JPEG.py", line 187, in Find
    r = r[st.GetBit()]
IndexError: list index out of range

class HuffmanTable:
    """
    A Huffman Table class
    """

    def __init__(self):
        self.root = []
        self.elements = []

    def BitsFromLengths(self, root, element, pos):
        if isinstance(root, list):
            if pos == 0:
                if len(root) < 2:
                    root.append(element)
                    return True
                return False
            for i in [0, 1]:
                if len(root) == i:
                    root.append([])
                if self.BitsFromLengths(root[i], element, pos - 1) == True:
                    return True
        return False

    def GetHuffmanBits(self, lengths, elements):
        self.elements = elements
        ii = 0
        for i in range(len(lengths)):
            for j in range(lengths[i]):
                self.BitsFromLengths(self.root, elements[ii], i)
                ii += 1

    def Find(self, st):
        r = self.root
        while isinstance(r, list):
            bit = st.GetBit()
            if bit is None:
                return None  # Handle the case when st.GetBit() returns None
            if bit >= len(r):
                return None  # Handle the case when the index is out of range
            r = r[bit]
        return r

    def GetCode(self, st):
        while True:
            res = self.Find(st)
            if res is None:
                return 0
            elif res != -1:
                return res