I'm not sure what this is needed for? bar:foo

For method name collision. #5762 (comment)

I meant the colons in the value, but now I see those are an artifact of the test fixture, not part of the code! My mistake.

Added docs.

@mostafakhudair @najdanovicivan @iRedds @the-gt99 @lonnieezell
Any comments?

I think this adds a lot of unnecessary complexity to have multiple ways of defining setters. So far the only problem we have is when we need to override setAttributes method. Since now we have setAttributes as deprecated and we're going forward with injectRawData() method. I'd rather use https://www.php.net/manual/en/reflectionmethod.getdeclaringclass.php to check if setAttributes is not from CodeIgniter\Entity or CodeIgniter\Entity\Entity class. So if method is not from base CI4 classes it can be handled as regular setter for $this->attributes['attributes']. The only problem with this one is BC in Entity classes which override the setAttributes method.

@najdanovicivan Thank you for your opinion.

The main reason of this PR is to avoid setter/getter method name conflicts,
not only for setAttributes().
See https://github.com/codeigniter4/CodeIgniter4/pull/7230/files#diff-b43fcc536c7ffa370ea5d043988d111223780b2dade0198d7b91818f9bd7ab62

As far as I remember, PSR does not recommend using the underscore character as a prefix for method names.
I have already expressed my opinion about the names of methods for accessing attributes more than once.
get<name>Attribute

We don't remove get<name>() getter.
So get<name>Attribute() may conflict to another column.

If there are columns parent and parent_attribute and
getParent() and getParentAttribute(),
getParentAttribute() is used when getting parent.
This is a breaking change.