parameter is set up by connecting the Statistics instance with an arbitrary statistics
source.
- %Statistics sources are <a href="http://www.boost.org/doc/libs/1_37_0/doc/html/signals.html">
+ %Statistics sources are <a href="http://www.boost.org/doc/libs/release/doc/html/signals.html">
Boost Signals</a> which are emitted periodically to provide new data.
*/