Improved return type for fluent methods in Context

[wouterj]

Q	A
Bug fix?	yes
New feature?	no
Doc updated	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	-
License	MIT

While the self return type is true, it is too loose. What is actually returned is $this (i.e. the class extending this abstract class). This means the following code is - strictly spoken - invalid:

$serializationContext = SerializationContext::create()
  ->setSerializeNull(true)
  ->setGroups(['api'])
;

$this->serializer->serialize($subject, 'json', $serializationContext)

As PHP does not have the static return type until PHP 8, I think adding this PHPdoc is the best possible solution to make static analysers and IDEs happy.

[goetas]

thank you!