Immutable Source of Mutable Instances

The Keykos factory is immutable and can thus be shared between regimes that are not allowed to communicate. That same factory may produce mutable objects to solve all sorts of pratical problems. The code that defines these mutable objects need not be examined to ensure the above communication property.

The Java patterns for creating new objects fail to match this pattern for sibling objects may share static mutable variables. Access to the source, or perhaps bytecodes, is necessary to ensure that this is not the case.

We need a precise definition of "immutable".