Product.kt example — remove nullable type on association property

[avarun42]

Manufacturer? -> Manufacturer

If you look at the docs in https://github.com/micronaut-projects/micronaut-data/blob/master/src/main/docs/guide/sql/dbc/sqlMapping/sqlAssociationFetching.adoc, they state:

an exception will occur since the manufacturer association is not Nullable.

Then state to solve this by:

in Kotlin add ? to the end of the constructor argument name

However the example already is nullable and has a ? at the end of the property type. This seems to be a mistake.

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[dstepanov]

It looks like it failed with Null can not be a value of a non-null type Manufacturer

[avarun42]

It looks like it failed with Null can not be a value of a non-null type Manufacturer

From my reading of this section of the docs though, it seems like this example snippet is supposed to throw an exception of this kind.

If you look at the Java example for the same section, the manufacturer relation is explicitly not marked as nullable. The Kotlin example isn't consistent with the Java example or with the written docs themselves.

[avarun42]

If somebody can point me to where to update the test to expect a thrown exception I can update this PR.

[dstepanov]

Can you rebase it and force push? So we will have a fresh run and see what test was failing.