class_docstr: Reads an svg file and exports paths to a JSON format.
  
  Only segments and Bezier curves are supported
docstr: Save to JSON.
code: def save_json(self, filename):
      """Save to JSON."""
      json_content = self.to_json()
  
      with open(filename, "w") as f:
          f.write(json_content)
  
file_path: nilearn/nilearn/plotting/glass_brain_files/svg_to_json_converter.py
imports: import json
  import re
  import sys
label_desc: Use image node_id 7 for calling the SVGToJSONConverter obj's underlying member method code with example usage: obj.save_json(filename) without return types