How to implement a service to manage the process of worksheet cell calculation

This example illustrates the use of the service which implements the DevExpress.XtraSpreadsheet.Services.ICustomCalculationService  interface and allows to manage the process of worksheet calculations.
The application creates log entries when worksheet calculation starts and finishes, when cell calculation begins and ends, when a cell with the circular reference starts and finishes its calculation.
Cells containing circular reference are indicated by drawing a red box within the cell.