Diagnostic(breakdownTree),
        };
        return Object.assign(p,
            {
              breakdownTree,
              cpuBreakdownTree,
              wallHistogramName,
              wallHistogramDescription,
              cpuHistogramName,
              cpuHistogramDescription,
              diagnostics,
            });
      });
      breakdownList.forEach(p => {
        // entry === {start:0, end:1, breakdownTree, cpuBreakdownTree}
        if (!histograms.getHistogramNamed(p.wallHistogramName)) 