The methods GsonBuilder#setFieldNamingPolicy and GsonBuilder#setFieldNamingStrategy both do the same, they assign a value to the fieldNamingPolicy field. This is not obvious from the documentation.

It would be good if the documentation clarified that the methods overwrite each other's changes. Possibly setFieldNamingPolicy could also be deprecated, because it is redundant, but this might not be a strong enough reason for a deprecation.