How to use the graphene.String function in graphene

from django.contrib.gis import geos

import graphene

import graphql_geojson

from . import models, types
from .testcases import SchemaTestCase


class CreatePlace(graphene.Mutation):
    place = graphene.Field(types.PlaceType)

    class Arguments:
        name = graphene.String(required=True)
        location = graphql_geojson.Geometry(required=True)

    @classmethod
    def mutate(cls, root, info, **args):
        place = models.Place.objects.create(**args)
        return cls(place=place)


class MutationsTests(SchemaTestCase):
    query = '''
    mutation CreatePlace($name: String!, $location: Geometry!) {
      createPlace(name: $name, location: $location) {
        place {
          id
          type
          geometry {

import graphene
from graphql import GraphQLError
from backend.likes.models import Like as LikeModel
from backend.posts.models import Post as PostModel
from backend.comments.models import Comment as CommentModel
from backend.likes.schemas.queries import LikeNode


class LikePost(graphene.Mutation):
    """
    Adds a like to the specified post.
    """
    class Arguments:
        post_unique_identifier = graphene.String(required=True, description="Unique identifier of the post")

    ' Fields '
    like = graphene.Field(LikeNode)

    def mutate(self, info, post_unique_identifier):
        if info.context.user.is_anonymous:
            raise GraphQLError('Not logged in.')
        post = PostModel.objects.get(unique_identifier=post_unique_identifier)
        try:
            new_like = LikeModel(content_object=post, user=info.context.user)
        except Exception as e:
            raise GraphQLError(e)
        else:
            new_like.save()
        return LikePost(like=new_like)

start_date = args.get('start_date', None)
        end_date = args.get('end_date', None)
        if start_date:
            discussion.active_start_date = start_date.replace(tzinfo=None)
        if end_date:
            discussion.active_end_date = end_date.replace(tzinfo=None)

        db.flush()
        discussion = cls.get(discussion_id)
        return UpdateDiscussion(discussion=discussion)


class LocalePreference(graphene.ObjectType):
    __doc__ = docs.LocalePreference.__doc__

    locale = graphene.String(description=docs.LocalePreference.locale)
    name = graphene.String(in_locale=graphene.String(required=True), description=docs.LocalePreference.name)
    native_name = graphene.String(description=docs.LocalePreference.native_name)

    def resolve_name(self, args, context, info):
        in_locale = args.get('in_locale') or None
        locale_model = models.Locale.get_or_create(in_locale)

        name = models.LocaleLabel.names_of_locales_in_locale([self.locale],
                                                             locale_model)
        if not name:
            # If the locale label does not exist, fallback on English
            locale_model = models.Locale.get_or_create('en')
            name = models.LocaleLabel.names_of_locales_in_locale([self.locale],
                                                                 locale_model)

        return name[self.locale]

def resolve_title(stop_info, info):
        return stop_info.title

    def resolve_lat(stop_info, info):
        return stop_info.lat

    def resolve_lon(stop_info, info):
        return stop_info.lon

class RouteConfig(ObjectType):
    id = String()
    title = String()
    directions = List(DirectionInfo)
    stops = List(StopInfo)
    stopInfo = Field(StopInfo, stopId = String())
    directionInfo = Field(DirectionInfo, directionId = String())

    # `parent` is a routeconfig.RouteConfig object

    def resolve_id(route_config, info):
        return route_config.id

    def resolve_title(route_config, info):
        return route_config.title

    def resolve_stopInfo(route_config, info, stopId):
        return route_config.get_stop_info(stopId)

    def resolve_directionInfo(route_config, info, directionId):
        return route_config.get_direction_info(directionId)

interfaces = (Item, )

    user_id = graphene.String()
    access_key = graphene.String()
    secret_key = graphene.String()
    is_active = graphene.Boolean()
    is_admin = graphene.Boolean()
    resource_policy = graphene.String()
    created_at = GQLDateTime()
    last_used = GQLDateTime()
    concurrency_used = graphene.Int()
    rate_limit = graphene.Int()
    num_queries = graphene.Int()
    user = graphene.UUID()

    ssh_public_key = graphene.String()

    vfolders = graphene.List('ai.backend.manager.models.VirtualFolder')
    compute_sessions = graphene.List(
        'ai.backend.manager.models.ComputeSession',
        status=graphene.String(),
    )

    # Deprecated
    concurrency_limit = graphene.Int(
        deprecation_reason='Moved to KeyPairResourcePolicy object as '
                           'max_concurrent_sessions field.')

    @classmethod
    def from_row(
        cls,
        context: Mapping[str, Any],

comment=item['comment']
            )

    etc_services = graphene.List(EtcServices)

    def resolve_etc_services(self, args, context, info):
        for item in query.run('select * from etc_services'):
            yield EtcServices(
                    name=item['name'],
                    port=item['port'],
                    protocol=item['protocol'],
                    aliases=item['aliases'],
                    comment=item['comment']
            )

    hash = graphene.List(Hash, directory=graphene.String(),
                               path=graphene.String()
    )

    def resolve_hash(self, args, context, info):
        if args.get('directory'): where = 'directory = \\"%s\\"' % utils.sanitize(args.get('directory'))
        if args.get('path'): where = 'path = \\"%s\\"' % utils.sanitize(args.get('path'))
        for item in query.run('select * from hash where %s' % where):
            yield Hash(
                    path=item['path'],
                    directory=item['directory'],
                    md5=item['md5'],
                    sha1=item['sha1'],
                    sha256=item['sha256']
            )

    interface_addresses = graphene.List(InterfaceAddresses)

temp = Tenant()

        if not_none(group):
            temp.group = TenantGroup.objects.get(pk=from_global_id(group)[1])

        return NewTenant(tenant=set_and_save(fields, input, temp))

class UpdateTenant(ClientIDMutation):
    tenant = Field(TenantNode)
    class Input:
        id = String(default_value=None)
        name = String(default_value=None)
        slug = String(default_value=None)
        group = String(default_value=None)
        description = String(default_value=None)
        comments = String(default_value=None)
        custom_field_values = String(default_value=None)

    @classmethod
    def mutate_and_get_payload(cls, input, context, info):
        group = input.get('group')

        temp = Tenant.objects.get(pk=from_global_id(input.get('id'))[1])

        if not_none(group):
            temp.group = TenantGroup.objects.get(pk=from_global_id(group)[1])

        fields = [ 'name', 'slug', 'description', 'comments', 'custom_field_values' ]
        return UpdateTenant(tenant=set_and_save(fields, input, temp))

class DeleteTenant(ClientIDMutation):
    tenant = Field(TenantNode)

if skip:
            qs = qs[skip::]

        if first:
            qs = qs[:first]

        return qs

    def resolve_votes(self, info, **kwargs):
        return Vote.objects.all()


class CreateLink(graphene.Mutation):
    id = graphene.Int()
    url = graphene.String()
    description = graphene.String()
    posted_by = graphene.Field(UserType)

    class Arguments:
        url = graphene.String()
        description = graphene.String()

    def mutate(self, info, url, description):
        user = info.context.user
        link = Link(
            url=url,
            description=description,
            posted_by=user,
        )
        link.save()

return await db_conn.scalar(query)
    else:
        raise TypeError('unexpected type for group_name_or_id')


class Group(graphene.ObjectType):
    id = graphene.UUID()
    name = graphene.String()
    description = graphene.String()
    is_active = graphene.Boolean()
    created_at = GQLDateTime()
    modified_at = GQLDateTime()
    domain_name = graphene.String()
    total_resource_slots = graphene.JSONString()
    allowed_vfolder_hosts = graphene.List(lambda: graphene.String)
    integration_id = graphene.String()

    scaling_groups = graphene.List(lambda: graphene.String)

    @classmethod
    def from_row(cls, context: Mapping[str, Any], row: RowProxy) -> Optional[Group]:
        if row is None:
            return None
        return cls(
            id=row['id'],
            name=row['name'],
            description=row['description'],
            is_active=row['is_active'],
            created_at=row['created_at'],
            modified_at=row['modified_at'],
            domain_name=row['domain_name'],
            total_resource_slots=row['total_resource_slots'].to_json(),

description="""Family cycle instances.""",
        args=proxy_args,
        resolver=get_nodes_by_ids)
    edges = Field(
        lambda: Edges,
        args=edge_args,
        description="""Graph edges""")
    nodes_edges = Field(
        lambda: NodesEdges,
        args=nodes_edges_args,
        resolver=get_nodes_edges)
    api_version = Int()
    cylc_version = String()
    last_updated = Float()
    meta = Field(DefMeta)
    newest_runahead_cycle_point = String()
    newest_cycle_point = String()
    oldest_cycle_point = String()
    reloaded = Boolean()
    run_mode = String()
    is_held_total = Int()
    state_totals = GenericScalar(resolver=resolve_state_totals)
    workflow_log_dir = String()
    time_zone_info = Field(TimeZone)
    tree_depth = Int()
    ns_defn_order = List(String)
    job_log_names = List(String)
    states = List(String)


class Job(ObjectType):
    class Meta: