Given the following *wrong* YAML fragment for a sample AvailabilityDefinition:

availability:
  nodeTypes:
    - mgnl-folder: mgnl:folder 

* The above is wrong because nodeTypes expects a list of strings, not maps.

When Map2BeanTransformer processes the "erroneous" YAML, It wrongly creates a collection containing maps, regardless of the generic type in the bean method signature.
Therefore, iterating over this collection will throw a ClassCastException.

Map2Bean should ignore entries which don't match the bean method's generic type, and warn accordingly.

See also

Collection<String> getNodeTypes()

Side note #1:
The issue arose with a wrong YAML app descriptor, which was produced by the Download as YAML action.
See the corresponding JCR bootstrap file on git.

Side note #2:
Correct YAML fragment would be:

availability:
  nodeTypes:
    - mgnl:product