'Internal method.
Reads a double word (4 bytes) from a buffer.'

def GetDWORD(self, buff, idx=0):

    result = (((buff[idx] + (buff[(idx + 1)] << 8)) + (buff[(idx + 2)] << 16)) + (buff[(idx + 3)] << 24))
    if (result == 4294967295):
        result = 0
    return result
