allow null in equals

[osavchenko]

No description provided.

[mnapoli]

Thank you for the PR, I'm not sure how I feel about that. If we go that route then why not accept anything in equals() then? But it feels doing it "just because we can", which isn't a good reason to add features.

[osavchenko]

For example, I have such method in my entity:

public function setType(DocumentType $type)
{
     $this->type = $type;
}

public function isPdf()
{
    return  DocumentType::PDF()->equals($this->getType());
}

But I can't set some initial value and when my entity is new and without value for $type - I get en error. So, I suggest to update this check.
Yes, I can write code like this:

public function isPdf()
{
    return  DocumentType::PDF() == $this->getType();
}

But here we have no strict check.

[mnapoli]

This line is redundant with the code, could you remove it?

[osavchenko]

Sure, fixed

[mnapoli]

OK after thinking about it it's really a small thing and could improve DX so why not.

I've added a comment, once fixed I can merge.

Thanks.

[mnapoli]

Thanks!