def parse_docstring(docstring, cls=None):
    """
    :return: return dict
        description - method description
        arguments - dict of dicts arg_name: {description, type_name, required}
        return - dict: {description, type}
    """
    def_arg_dict = lambda: {'description': None,
                            'type_name': None,
                            'required': False,
                            }
    description, fields_lines = split_docstring(docstring)
    arguments_dict = defaultdict(def_arg_dict)
    return_value_types = []
    #parse fields
    return_description = ''
    for docstring_line in fields_lines:
        if _ignored_field(docstring_line):
            continue
        #parse inherits
        if docstring_line.startswith('@inherits'):
            if not cls:
                raise MethodParsingException()
            inherit_tmp = docstring_line.split(None, 1)[1]
            inherit_str = inherit_tmp.split(':class:', 1)[1]
            result = _parse_inherit(cls, inherit_str)

            description = description or result['description']
            for arg_name, update_dict in result['arguments'].items():
                arguments_dict[arg_name].update(update_dict)
            return_value_types = result['return']['type_name']
            return_description = result['return']['description']
        #parse return value
        elif docstring_line.startswith(':rtype:'):
            class_name = __get_class_name(cls)
            types_str = docstring_line.split(None, 1)[1]
            return_value_types = types_str.replace('\n', '').strip(':').strip()
            if return_value_types.startswith('class:`.'):
                return_value_types = return_value_types.replace('class:`.', 'class:`'+class_name+'.')
        #parse return description
        elif docstring_line.startswith(':return:'):
            return_description = docstring_line.split(None, 1)[1].strip()
        #parse arguments
        else:
            arg_name, update_dict = _parse_docstring_field(cls, docstring_line)
            arguments_dict[arg_name].update(update_dict)
    #check fields
    _check_arguments_dict(arguments_dict)
    if not return_value_types:
        raise MethodParsingException('Can not get return types for method')
    return {'description': description,
            'arguments': arguments_dict,
            'return': {'description': return_description,
                       'type_name': return_value_types}}
:return: return dict
        description - method description
        arguments - dict of dicts arg_name: {description, type_name, required}
        return - dict: {description, type}