code: def build_graph_from_str(graph_str: str) -> nx.DiGraph:
      """
      User-friendly function that returns a networkx graph based on the graph string.
  
      Formats supported: dot, gml, daggity
  
      The `graph_str` parameter can refer to the path of a text file containing the encoded graph or contain the actual encoded graph as a string.
  
      :param graph_str: a string containing the filepath or the encoded graph
      :type graph_str: str
  
      :returns: a networkx directed graph object
      """
      # some preprocessing steps
      if re.match(r".*\.txt", graph_str):
          text_file = open(graph_str, "r")
          graph_str = text_file.read()
          text_file.close()
      if re.match(
          r"^dag", graph_str
      ):  # Convert daggity output to dot format
          graph_str = daggity_to_dot(graph_str)
      if isinstance(graph_str, str):
          graph_str = graph_str.replace("\n", " ")
  
      # parsing the correct graph based on input graph format
      if re.match(r".*\.dot", graph_str):
          # load dot file
          try:
              import pygraphviz as pgv
  
              return nx.DiGraph(
                  nx.drawing.nx_agraph.read_dot(graph_str)
              )
          except Exception as e:
              _logger.error(
                  "Pygraphviz cannot be loaded. "
                  + str(e)
                  + "\nTrying pydot..."
              )
              try:
                  import pydot
  
                  return nx.DiGraph(
                      nx.drawing.nx_pydot.read_dot(graph_str)
                  )
              except Exception as e:
                  _logger.error(
                      "Error: Pydot cannot be loaded. " + str(e)
                  )
                  raise e
      elif re.match(r".*\.gml", graph_str):
          return nx.DiGraph(nx.read_gml(graph_str))
      elif re.match(r".*graph\s*\{.*\}\s*", graph_str):
          try:
              import pygraphviz as pgv
  
              graph = pgv.AGraph(graph_str, strict=True, directed=True)
              return nx.drawing.nx_agraph.from_agraph(graph)
          except Exception as e:
              _logger.error(
                  "Error: Pygraphviz cannot be loaded. "
                  + str(e)
                  + "\nTrying pydot ..."
              )
              try:
                  import pydot
  
                  P_list = pydot.graph_from_dot_data(graph_str)
                  return nx.DiGraph(
                      nx.drawing.nx_pydot.from_pydot(P_list[0])
                  )
              except Exception as e:
                  _logger.error(
                      "Error: Pydot cannot be loaded. " + str(e)
                  )
                  raise e
      elif re.match(".*graph\s*\[.*\]\s*", graph_str):
          return nx.DiGraph(nx.parse_gml(graph_str))
      else:
          _logger.error(
              "Error: Please provide graph (as string or text file) in dot or gml format."
          )
          _logger.error("Error: Incorrect graph format")
          raise ValueError
  
imports: import itertools
  import logging
  import re
  from abc import abstractmethod
  from typing import Any, List, Protocol
  import networkx
  from networkx.algorithms.dag import has_cycle
  from dowhy.utils.api import parse_state
  from dowhy.utils.graph_operations import daggity_to_dot
label_desc: Use image node_id 20 for calling a global function with example usage: build_graph_from_str(graph_str) and returns: nx, nx, nx, nx, nx, nx