code: def render(self):
      writer = {
          "name": "BlockMatrixRectanglesWriter",
          "path": self.path,
          "rectangles": self.rectangles,
          "delimiter": self.delimiter,
          "binary": self.binary,
      }
      return escape_str(json.dumps(writer))
  
imports: import abc
  import json
  from ..typecheck import typecheck_method, sequenceof, nullable, enumeration
  from ..expr.types import tvoid, tstr
  from ..utils.misc import escape_str
label_desc: Use image node_id 2 for calling the BlockMatrixRectanglesWriter obj's underlying member method code with example usage: obj.render() and returns: escape_str