Pico Container Good Citizens

What is a good citizen in OO:

from here

As a good citizen, I...

• Keep a consistent state at all times - init() or populate() is a code smell.
• Have no static fields or methods
• Never expect or return null.
• FailFast - even when constructing.
• Am Easy to test- all dependent object I use can be passed to me, often in my constructor (typically as Mock Objects).
• Accept dependent object that can easily be substituted with Mock Objects (I don't use Concrete Class Dependency).
• Chain multiple constructors to a common place (using this(...)).
• Always define hashCode() alongside equals()
• Prefer immutable value objects that I can easily throw away.
• Have a special value for 'nothing' - e.g. Collections.EMPTY_SET.
• Raise checked exceptions when the caller asked for something unreasonable - e.g. open a non-existant file.
• Raise unchecked exceptions when I can't do something reasonable that the caller asked of me - e.g. disk error when reading from an opened file.
• Only catch exceptions that can be handled fully.
• Only log information that someone needs to see.

Classes that are designed for Constructor Injection are better citizens than those that are not.