An instance of this class contains a presentation-time CCT for the given thread in the compact, flattened form, that is also fast
to generate and save/retrieve.
Can represent data only on the method level "view" AKA "aggregation level".
Management of the CPU profiling results snapshot.
A CPU snapshot is created from the runtime CCTs for all profiled threads, that are provided by CPUCallGraphBuilder.
Initially it contains only these same (logically) CCTs (in instances of CPUCCTContainer), but in compact "flattened"
format that takes less space in memory, and represented in microseconds, cleansed time.
When the user starts to open CCT nodes for the given thread, the relevant objects (PrestimeCPUCCTNodes) are generated lazily
for touched nodes out of the initial compact representation.
This class is simply a container for instrumentation timing data that needs to be passed around between
a number of different objects when processing CPU profiling results.