How to use the maxminddb.compat.byte_from_int function in maxminddb

def _decode_pointer(self, size, offset):
        pointer_size = ((size >> 3) & 0x3) + 1
        new_offset = offset + pointer_size
        pointer_bytes = self._buffer[offset:new_offset]
        packed = pointer_bytes if pointer_size == 4 else struct.pack(
            b'!c', byte_from_int(size & 0x7)) + pointer_bytes
        unpacked = int_from_bytes(packed)
        pointer = unpacked + self._pointer_base + \
            self._pointer_value_offset[pointer_size]
        if self._pointer_test:
            return pointer, new_offset
        (value, _) = self.decode(pointer)
        return value, new_offset

def _decode_pointer(self, size, offset):
        pointer_size = (size >> 3) + 1

        buf = self._buffer[offset : offset + pointer_size]
        new_offset = offset + pointer_size

        if pointer_size == 1:
            buf = byte_from_int(size & 0x7) + buf
            pointer = struct.unpack(b"!H", buf)[0] + self._pointer_base
        elif pointer_size == 2:
            buf = b"\x00" + byte_from_int(size & 0x7) + buf
            pointer = struct.unpack(b"!I", buf)[0] + 2048 + self._pointer_base
        elif pointer_size == 3:
            buf = byte_from_int(size & 0x7) + buf
            pointer = struct.unpack(b"!I", buf)[0] + 526336 + self._pointer_base
        else:
            pointer = struct.unpack(b"!I", buf)[0] + self._pointer_base

        if self._pointer_test:
            return pointer, new_offset
        (value, _) = self.decode(pointer)
        return value, new_offset

def _read_node(self, node_number, index):
        base_offset = node_number * self._metadata.node_byte_size

        record_size = self._metadata.record_size
        if record_size == 24:
            offset = base_offset + index * 3
            node_bytes = b'\x00' + self._buffer[offset:offset + 3]
        elif record_size == 28:
            (middle, ) = struct.unpack(
                b'!B', self._buffer[base_offset + 3:base_offset + 4])
            if index:
                middle &= 0x0F
            else:
                middle = (0xF0 & middle) >> 4
            offset = base_offset + index * 4
            node_bytes = byte_from_int(middle) + self._buffer[offset:offset + 3]
        elif record_size == 32:
            offset = base_offset + index * 4
            node_bytes = self._buffer[offset:offset + 4]
        else:
            raise InvalidDatabaseError(
                'Unknown record size: {0}'.format(record_size))
        return struct.unpack(b'!I', node_bytes)[0]