class_docstr: Mark an instantaneous event that occurred at some point.
  
  Args:
      msg: ASCII message to associate with the event.
code: def __call__(self, data):
      _nvtx.markA(self.msg)
      return data
  
imports: from __future__ import annotations
  from monai.transforms.traits import RandomizableTrait
  from monai.transforms.transform import Transform
  from monai.utils import optional_import
label_desc: Use image node_id 2 for calling the Mark obj's underlying member method code with example usage: obj.__call__(data) and returns: data