A custom ClassLoader that knows how to load classes from a set of attachments. The attachments themselves only need to provide JAR streams, and so could be fetched from a database, local disk, etc. Constructing an AttachmentsClassLoader is somewhat expensive, as every attachment is scanned to ensure that there are no overlapping file paths.

A simple lookup table of city names to their coordinates. Lookups are case insensitive.

Info about a network node that acts on behalf of some form of contract party.

A labelled WorldCoordinate, where the label is human meaningful. For example, the name of the nearest city. Labels should not refer to non-landmarks, for example, they should not contain the names of organisations.

A service hub simply vends references to the other services a node has. Some of those services may be missing or mocked out. This class is useful to pass to chunks of pluggable code that might have need of many different kinds of functionality and you dont want to hard-code which types in the interface.

A latitude/longitude pair.