A new method [getTotalGcCpuTime()] has been added to [java.lang.management.MemoryMXBean], that returns a long result with the accumulated CPU time in nanoseconds for GC related activity.

Although added as a standard API, possible usage may be in conjunction with the `ProcessCpuTime` property defined by the JDK-specific management interface [com.sun.management.OperatingSystemMXBean].