langchain/document_loaders/obsidian.py/ObsidianLoader/_parse_front_matter
class ObsidianLoader:    def _parse_front_matter(self, content: str) -> dict:
        """Parse front matter metadata from the content and return it as a dict."""
        if not self.collect_metadata:
            return {}
        match = self.FRONT_MATTER_REGEX.search(content)
        front_matter = {}
        if match:
            lines = match.group(1).split("\n")
            for line in lines:
                if ":" in line:
                    key, value = line.split(":", 1)
                    front_matter[key.strip()] = value.strip()
                else:
                    # Skip lines without a colon
                    continue
        return front_matter