code: def _yaml_front_matter_s(filename):
      lines = []
      reading = False
      with open(filename) as f:
          for line in f:
              trimmed = line.rstrip()
              if not trimmed.lstrip():
                  continue
              if trimmed == "---":
                  if reading:
                      break
                  reading = True
              elif reading:
                  lines.append(trimmed)
              else:
                  break
      return "\n".join(lines) if lines else None
  
file_path: guildai/guild/yaml_util.py
imports: import os
  import re
  import yaml
label_desc: Use image node_id 5 for calling a global function with example usage: _yaml_front_matter_s(filename) and returns: unknown