"Class must not be null" error when Consumer uses 2 level generis

[oleksiimiroshnyk]

Describe the bug

I have a consumer bean:

BindingConsumer<Message<String>> consumer(){...}

This is my class that implements Consumer interface:

class BindingConsumer<T> implements Consumer<T>

When I run test it fails with error:

Caused by: java.lang.IllegalArgumentException: Class must not be null
	at org.springframework.util.Assert.notNull(Assert.java:182) ~[spring-core-7.0.3.jar:7.0.3]
	at org.springframework.core.ResolvableType.forClassWithGenerics(ResolvableType.java:1172) ~[spring-core-7.0.3.jar:7.0.3]
	at org.springframework.cloud.function.context.catalog.FunctionTypeUtils.resolveType(FunctionTypeUtils.java:386) ~[spring-cloud-function-context-5.0.1.jar:5.0.1]
	at org.springframework.cloud.function.context.catalog.FunctionTypeUtils.getInputType(FunctionTypeUtils.java:436) ~[spring-cloud-function-context-5.0.1.jar:5.0.1]
	at org.springframework.cloud.function.context.FunctionRegistration.type(FunctionRegistration.java:129) ~[spring-cloud-function-context-5.0.1.jar:5.0.1]
	at org.springframework.cloud.function.context.catalog.BeanFactoryAwareFunctionRegistry.lookup(BeanFactoryAwareFunctionRegistry.java:192) ~[spring-cloud-function-context-5.0.1.jar:5.0.1]

If I change my class signature:

class BindingConsumer<T> implements Consumer<Message<T>>

and create bean:

BindingConsumer<String> consumer(){...}

Everything works fine.

Looks like a bug in
org.springframework.cloud.function.context.catalog.FunctionTypeUtils#resolveType

			return ResolvableType.forClassWithGenerics(typeWithGenerics.getRawClass(),
				resolvedGenerics.toArray(new ResolvableType[0])).getType();

typeWithGenerics.getRawClass() returns null. I think it can be more smart and return Message