code: def write_security(self, security, bytes_per_line=75):
          
  
          for start in range(0, len(security), bytes_per_line):
              self.write_record('G', security[start:start + bytes_per_line])
docs: Write the security signature::
  
              writer.write_security('ABCDEF')
              # -> GABCDEF
  
          If a signature of more than 75 bytes is used the G record will be
          broken into multiple lines according to the IGC file specification.
          This rule can be configured with the ``bytes_per_line`` parameter if
          necessary.
  
          :param security: the security signature
          :param bytes_per_line: the maximum number of bytes per line
              (default: ``75``)