Patch contains three new files:
KeyedPriorityBuffer - class based on PriorityBuffer; with additional support for fast search and remove
KeyedBuffer - general interface for all buffers containing key-identified elements
TestKeyedPriorityBuffer - JUnit test cases
Rationale for introducing new types: I needed a buffer with additional fast search (both get and remove) of elements. I wanted a buffer with search characteristics of a HashMap. But one cannot simply put together a Buffer with a HashMap since the Map needs to have an access to the internal buffer data structures to manage fast remove(key).
KeyedPriorityBuffer is mixin of a PriorityBuffer with a internal HashMap managing fast search operations.
KeyedBuffer is a general interface for all such buffers supporting key operations. It extends Map rather than Collection since imho it is more natural.