- DataTree members scount, initialized and method listACLEquals are never used
- transform if(!C) B else A to if(C) A else B (removes one indirection to follow for the brain)
- remove unused imports and one annotation
- add method getApproximateDataSize to DataNode (I work towards an immutable DataNode without public properties)
- move assignments (lastPrefix = getMaxPrefixWithQuota(path)) out of if statements
- combine nested if statements: if A if B then C => if A && B => C
- make ACL maps private and add getAclSize() to hide implementation details of the ACLs.