def iterkeys(self, key_type=None, return_all_keys=False):
if(key_type is not None):<EOL><INDENT>the_key = str(key_type)<EOL>if the_key in self.__dict__:<EOL><INDENT>for key in self.__dict__[the_key].keys():<EOL><INDENT>if return_all_keys:<EOL><INDENT>yield self.__dict__[the_key][key]<EOL><DEDENT>else:<EOL><INDENT>yield key            <EOL><DEDENT><DEDENT><DEDENT><DEDENT>else:<EOL><INDENT>for keys in self.items_dict.keys():<EOL><INDENT>yield keys<EOL><DEDENT><DEDENT>
Returns an iterator over the dictionary's keys.
            @param key_type if specified, iterator for a dictionary of this type will be used. 
                   Otherwise (if not specified) tuples containing all (multiple) keys
                   for this dictionary will be generated.
            @param return_all_keys if set to True - tuple of keys is retuned instead of a key of this type.