Mentions has a Java level dependency on some code internal to the Confluence Rest plugin. This means there may be future issues with compatibility in the future. We should try to remove this.

From Charles Miller:

No. We shouldn't have ANY dependency on the Java code in the Confluence REST plugin from outside the plugin.
Creating Java-level dependencies between arbitrary bits of the code-base that were never meant to be public APIs, while it can save time, is what turns Confluence development into a poison-coated pit full of snakes.