Design an IPv4 Address Iterator

Design a class that iterates through IPv4 addresses. An IPv4 address is a string in the form `a.b.c.d`, where each octet is an integer from `0` to `255`. Implement an iterator with the following behavior: - The constructor receives: - `start_ip`: the first IPv4 address in the sequence - `end_ip`: the last IPv4 address that may be returned - `step`: a positive integer increment - The increment is fixed for the lifetime of the object and is provided in the constructor, not passed into `next()`. - `next()` returns the current IP address and then advances by `step` addresses. - `has_next()` returns whether another valid address can still be returned without passing `end_ip`. You should correctly handle carry between octets. For example: - incrementing `10.0.0.255` by 1 gives `10.0.1.0` - incrementing `192.168.1.254` by 2 gives `192.168.2.0` Assume all input IP strings are valid and `start_ip <= end_ip`. Example: - `start_ip = "192.168.0.254"` - `end_ip = "192.168.1.4"` - `step = 2` The iterator should return: - `192.168.0.254` - `192.168.1.0` - `192.168.1.2` - `192.168.1.4` Follow-up: What internal representation would you choose to simplify the implementation and avoid repeated string parsing?