docs: def is_line_in_file(filename: str, line: str) -> bool:
      """
      Detects whether a line is present within a file.
  
      Args:
          filename: file to check
          line: line to search for (as an exact match)
      """
      assert "\n" not in line
      with open(filename, "r") as file:
          for fileline in file:
              if fileline == line:
                  return True
          return False