def METHOD_NAME(input_file: str) -> dict[str, list[str]]:
    """Parses the contents that are being received from Helm.
    Helm will send us input that follows the following format:
    ```yaml
    ---
    # Source: filename.yaml
    data:
      key: value
    ```
    Since there are cases in which the same source may produce more than
    one YAML structure, the returned type represents this with a dictionary
    of lists, in which the key is the source filename and each item in the list
    is the content following the `# Source: ...` header.
    """
    result = defaultdict(list)
    template_files = []
    with open(input_file, "r", encoding="utf-8") as f:
        template_files = f.read().split("---")
    for template in template_files:
        lines = [line for line in template.splitlines() if line and len(line) > 0]
        if not lines:
            continue
        template_name = lines[0][len(_SOURCE_FILENAME_PREFIX) :]
        result[template_name].append("\n".join(lines[1:]))
    return result