A datasource contains information how to create a connection to a database, such as,
which database driver should be used, for which user should a connection be established, etc.
The context stores datasources under a given name.
allows to access and modify the configuration data for registered data source.
The main purpose of this interface is to allow you to register data sources which you know
by URL only, and have not yet loaded.
Also, it hides the details of the configuration data where the data source registrations
are maintained, so if possible at all, you should use this interface, instead of modifying or
querying the configuration data directly.
