class_docstr: Raised when input data cannot be merged into a variable font.
code: def __str__(self):
      offender_index, offender = self.offender
      location = ""
      if offender:
          location = f"\n\nThe problem is likely to be in {offender}:\n"
      context = "".join(reversed(self.stack))
      basic = textwrap.fill(
          f"Couldn't merge the fonts, because {self.reason}. "
          f"This happened while performing the following operation: {context}",
          width=78,
      )
      return "\n\n" + basic + location + self.details
  
imports: import textwrap
label_desc: Use image node_id 6 for calling the VarLibMergeError obj's underlying member method code with example usage: obj.__str__() and returns: unknown