Current code will not compile in Eclipse

[22ka]

I have imported the code into eclipse as a maven project.
Getting errors in:

ManageMailboxAccessDialog.java
line 35 The method values() is undefined for the type Mailbox.Permission

Mailbox.java
line 62 Type mismatch: cannot convert from Map<Object,Object> to Map<Principal,Mailbox.Permission>
line 64 The target type of this expression must be a functional interface.