docs: function(stack) {
      if (exports.async_trace_limit <= 0) {
          return;
      }
  
      var count = exports.async_trace_limit - 1;
      var previous = stack;
  
      while (previous && count > 1) {
          previous = previous.__previous__;
          --count;
      }
  
      if (previous) {
          delete previous.__previous__;
      }
  }