With following statement in yang model:

list property {
key "key";
leaf key

}

exception is thrown:

java.lang.ClassCastException: org.opendaylight.yangtools.binding.generator.util.Types$ConcreteTypeImpl cannot be cast to org.opendaylight.yangtools.sal.binding.model.api.GeneratedTransferObject
at org.opendaylight.yangtools.sal.java.api.generator.BuilderTemplate.generateConstructor(BuilderTemplate.java:1006)
at org.opendaylight.yangtools.sal.java.api.generator.BuilderTemplate.body(BuilderTemplate.java:398)
at org.opendaylight.yangtools.sal.java.api.generator.BaseTemplate.generate(BaseTemplate.java:73)
at org.opendaylight.yangtools.sal.java.api.generator.BuilderGenerator.generate(BuilderGenerator.java:58)
at org.opendaylight.yangtools.sal.java.api.generator.GeneratorJavaFile.generateTypeToJavaFile(GeneratorJavaFile.java:126)
at org.opendaylight.yangtools.sal.java.api.generator.GeneratorJavaFile.generateToFile(GeneratorJavaFile.java:73)

This is caused because of 2 methods with same name (getKey) are generated, first for list statement to get key, second as a getter for leaf node.