code: public static void before(String label) {
          TracyThreadContext ctx = threadContext.get();
          if (isValidContext(ctx))    {
              ctx.push(label);
          }
      }
docs: Call before starting an operation you want to capture elapsed time for.<br>
  You can nest before() calls if you want to trace both caller and callee methods,
  but make sure you call after() for every before().
  @param label is the name you will see in the trace event report of graph node representation or timeline