code: def parse(self, valstr):
          # type: (bytes) -> None
          '''
          Parse an El Torito section header from a string.
  
          Parameters:
           valstr - The string to parse.
          Returns:
           Nothing.
          '''
          if self._initialized:
              raise pycdlibexception.PyCdlibInternalError('El Torito Section Header already initialized')
  
          (self.header_indicator, self.platform_id, self.num_section_entries,
           self.id_string) = struct.unpack_from(self.FMT, valstr, 0)
  
          self._initialized = Truf parse(self, valstr):
          # type: (bytes) -> None
          '''
          Parse an El Torito section header from a string.
  
          Parameters:
           valstr - The string to parse.
          Returns:
           Nothing.
          '''
          if self._initialized:
              raise pycdlibexception.PyCdlibInternalError('El Torito Section Header already initialized')
  
          (self.header_indicator, self.platform_id, self.num_section_entries,
           self.id_string) = struct.unpack_from(self.FMT, valstr, 0)
  
          self._initialized = True
docs: Parse an El Torito section header from a string.
  
          Parameters:
           valstr - The string to parse.
          Returns:
           Nothing.