anchor.diff:  It's when `StringBuilder.delete()` is called which calls `System.arraycopy()`.
   The issue is that 1 million characters need to be shifted in very small increments:
   
  -image:native-reference-perf-flamegraph-symbols.png[Perf flamegraph with symbols]
  +image::native-reference-perf-flamegraph-symbols.png[Perf flamegraph with symbols]
   
   === Multi-Thread
   
  
positive.code: ${FG_HOME}/flamegraph.pl out.perf-folded > flamegraph.svg
  ----
  
  image:native-reference-multi-flamegraph-separate-threads.png[Muti-thread perf flamegraph with separate threads]
  
  The flamegraph produced looks odd. Each thread is treated independently even though they all do the same work.
  This makes it difficult to have a clear picture of the bottlenecks in the program.
  
negative.code: ${FG_HOME}/flamegraph.pl out.perf-folded > flamegraph.svg
  ----
  
  image::native-reference-multi-flamegraph-joined-threads.png[Muti-thread perf flamegraph with joined threads]
  
  When you open the flamegraph, you will see all threads' work collapsed into a single area.
  Then, you can clearly see that there's some locking that could affect performance.
  