code: def from_string(string, mime=False, filename=None):
      
      head, foot = _string_details(string)
      ext = ext_from_filename(filename) if filename else None
      return _magic(head, foot, mime, ext)
docs: Reads in string, attempts to identify content based
      off magic number and will return the file extension.
      If mime is True it will return the mime type instead.
      If filename is provided it will be used in the computation.
  
      :param string: string representation to check
      :param mime: Return mime, not extension
      :param filename: original filename
      :return: guessed extension or mime