def _set_raw_return(self, sep):
        """Set the output raw return section

        :param sep: the separator of current style

        """
        raw = ''
        if self.dst.style['out'] == 'numpydoc':
            raw += '\n'
            spaces = ' ' * 4
            with_space = lambda s: '\n'.join([self.docs['out']['spaces'] + spaces + l.lstrip() if i > 0 else l for i, l in enumerate(s.splitlines())])
            raw += self.dst.numpydoc.get_key_section_header('return', self.docs['out']['spaces'])
            if self.docs['out']['rtype']:
                rtype = self.docs['out']['rtype']
            else:
                rtype = 'type'
            # case of several returns
            if type(self.docs['out']['return']) is list:
                for ret_elem in self.docs['out']['return']:
                    # if tuple (name, desc, rtype) else string desc
                    if type(ret_elem) is tuple and len(ret_elem) == 3:
                        rtype = ret_elem[2]
                        if rtype is None:
                            rtype = ''
                        raw += self.docs['out']['spaces']
                        if ret_elem[0]:
                            raw += ret_elem[0] + ' : '
                        raw += rtype + '\n' + self.docs['out']['spaces'] + spaces + with_space(ret_elem[1]).strip() + '\n'
                    else:
                        # There can be a problem
                        raw += self.docs['out']['spaces'] + rtype + '\n'
                        raw += self.docs['out']['spaces'] + spaces + with_space(str(ret_elem)).strip() + '\n'
            # case of a unique return
            elif self.docs['out']['return'] is not None:
                raw += self.docs['out']['spaces'] + rtype
                raw += '\n' + self.docs['out']['spaces'] + spaces + with_space(self.docs['out']['return']).strip() + '\n'
        elif self.dst.style['out'] == 'google':
            raw += '\n'
            spaces = ' ' * 2
            with_space = lambda s: '\n'.join([self.docs['out']['spaces'] + spaces +\
                                                    l.lstrip() if i > 0 else\
                                                    l for i, l in enumerate(s.splitlines())])
            raw += self.dst.googledoc.get_key_section_header('return', self.docs['out']['spaces'])
            if self.docs['out']['rtype']:
                rtype = self.docs['out']['rtype']
            else:
                rtype = None
            # case of several returns
            if type(self.docs['out']['return']) is list:
                for ret_elem in self.docs['out']['return']:
                    # if tuple (name=None, desc, rtype) else string desc
                    if type(ret_elem) is tuple and len(ret_elem) == 3:
                        rtype = ret_elem[2]
                        if rtype is None:
                            rtype = ''
                        raw += self.docs['out']['spaces'] + spaces
                        raw += rtype + ': ' + with_space(ret_elem[1]).strip() + '\n'
                    else:
                        # There can be a problem
                        if rtype:
                            raw += self.docs['out']['spaces'] + spaces + rtype + ': '
                            raw += with_space(str(ret_elem)).strip() + '\n'
                        else:
                            raw += self.docs['out']['spaces'] + spaces + with_space(str(ret_elem)).strip() + '\n'
            # case of a unique return
            elif self.docs['out']['return'] is not None:
                if rtype:
                    raw += self.docs['out']['spaces'] + spaces + rtype + ': '
                    raw += with_space(self.docs['out']['return']).strip() + '\n'
                else:
                    raw += self.docs['out']['spaces'] + spaces + with_space(self.docs['out']['return']).strip() + '\n'
        elif self.dst.style['out'] == 'groups':
            pass
        else:
            with_space = lambda s: '\n'.join([self.docs['out']['spaces'] + l if i > 0 else l for i, l in enumerate(s.splitlines())])
            if self.docs['out']['return']:
                if not self.docs['out']['params']:
                    raw += '\n'
                raw += self.docs['out']['spaces'] + self.dst.get_key('return', 'out') + sep + with_space(self.docs['out']['return'].rstrip()).strip() + '\n'
            if self.docs['out']['rtype']:
                if not self.docs['out']['params']:
                    raw += '\n'
                raw += self.docs['out']['spaces'] + self.dst.get_key('rtype', 'out') + sep + self.docs['out']['rtype'].rstrip() + '\n'
        return raw
Set the output raw return section

        :param sep: the separator of current style