class_docstr: Footnote Extension. 
class_docstr_tok: ["Footnote","Extension","."]
docstr: Setup configs. 
docstr_tok: ["Setup","configs","."]
code: def __init__(self, **kwargs):
      """Setup configs."""
  
      self.config = {
          "PLACE_MARKER": [
              "///Footnotes Go Here///",
              "The text string that marks where the footnotes go",
          ],
          "UNIQUE_IDS": [
              False,
              "Avoid name collisions across multiple calls to `reset()`.",
          ],
          "BACKLINK_TEXT": [
              "&#8617;",
              "The text string that links from the footnote to the reader's place.",
          ],
          "SUPERSCRIPT_TEXT": [
              "{}",
              "The text string that links from the reader's place to the footnote.",
          ],
          "BACKLINK_TITLE": [
              "Jump back to footnote %d in the text",
              "The text string used for the title HTML attribute of the backlink. "
              "%d will be replaced by the footnote number.",
          ],
          "SEPARATOR": [":", "Footnote separator."],
      }
      """ Default configuration options. """
      super().__init__(**kwargs)
  
      # In multiple invocations, emit links that don't get tangled.
      self.unique_prefix = 0
      self.found_refs: dict[str, int] = {}
      self.used_refs: set[str] = set()
  
      self.reset()
  
imports: from __future__ import annotations
  from .None import Extension
  from ..blockprocessors import BlockProcessor
  from ..inlinepatterns import InlineProcessor
  from ..treeprocessors import Treeprocessor
  from ..postprocessors import Postprocessor
  from ..None import util
  from collections import OrderedDict
  import re
  import copy
  import xml.etree.ElementTree
label_desc: Use image node_id 1 to create a new FootnoteExtension object from inherited base classes: Extension with example: obj = FootnoteExtension()