code: def is_root_node(causal_graph: DirectedGraph, node: Any) -> bool:
      return list(causal_graph.predecessors(node)) == []
  
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 1 for calling a global function with example usage: is_root_node(causal_graph, node) and returns: unknown