code: def _get_indent(line: str) -> Optional[int]:
      """Get the number of whitespaces at the beginning of the given line.
      If the line is empty, or if it contains just whitespace and a newline,
      return None.
      """
      if _EMPTY_LINE_RE.match(line) is not None:
          return None
  
      match = _SPACES_RE.match(line)
      return match.end() if match is not None else 0
  
file_path: streamlit/lib/streamlit/echo.py
imports: import ast
  import contextlib
  import re
  import textwrap
  import traceback
  from typing import Any, Dict, Iterable, Optional
  from streamlit.runtime.metrics_util import gather_metrics
label_desc: Use image node_id 3 for calling a global function with example usage: _get_indent(line) and returns: unknown, None