This interface is used to compute the help context for a freeform project.
Each
ProjectNature should register an implementation in its lookup.
See
HelpIDFragmentProvider.getHelpIDFragment to find out what are the requirements on the help
id fragments.
If it is necessary to compute a help context for a freeform project, all
HelpIDFragmentProvider s registered in the project's lookup are asked to
provide the fragments.