nodes: 0, module; 1, function_definition; 2, function_name:writePathogenIndex; 3, parameters; 4, block; 5, identifier:self; 6, identifier:fp; 7, expression_statement; 8, expression_statement; 9, comment:"""
          Write a file of pathogen indices and names, sorted by index.
  
          @param fp: A file-like object, opened for writing.
          """; 10, call; 11, identifier:print; 12, argument_list; 13, call; 14, keyword_argument; 15, attribute; 16, generator_expression; 17, identifier:file; 18, identifier:fp; 19, string; 20, identifier:join; 21, binary_operator:'%d %s' % (index, name); 22, for_in_clause; 23, string_content; 24, string; 25, tuple; 26, tuple_pattern; 27, call; 28, escape_sequence:\n; 29, string_content:%d %s; 30, identifier:index; 31, identifier:name; 32, identifier:index; 33, identifier:name; 34, identifier:sorted; 35, generator_expression; 36, tuple; 37, for_in_clause; 38, identifier:index; 39, identifier:name; 40, tuple_pattern; 41, call; 42, identifier:name; 43, identifier:index; 44, attribute; 45, argument_list; 46, attribute; 47, identifier:items; 48, identifier:self; 49, identifier:_pathogens
code: def writePathogenIndex(self, fp):
          """
          Write a file of pathogen indices and names, sorted by index.
  
          @param fp: A file-like object, opened for writing.
          """
          print('\n'.join(
              '%d %s' % (index, name) for (index, name) in
              sorted((index, name) for (name, index) in self._pathogens.items())
          ), file=fp)