TIF: Minor code improvement

- Removed unnecessary 'final' keywords for private methods
- Removed unnecessary interface modifiers
- Added a missing ‘final’ keyword
- Simplified if statements
- Removed Javadoc links pointing to itself
- Removed redundant conditional expressions
- Removed unnecessary return statements
- Replaced explicit types with <>
- Removed an unnecessary unboxing
- Removed a redundant initializer
- Fixed typos

Change-Id: I1d137fda70192b33dd00e92ab01396519135ab39