How to use the catalogue.models.Organization function in catalogue

return self.readonly_fields
    
    
@admin.register(models.Record)
class RecordAdmin(admin.ModelAdmin):
    list_display = ("id", "identifier", "title",)
    inlines = [StyleInline,]
    readonly_fields = ('publication_date','modified',)
    
    def get_readonly_fields(self, request, obj=None):
        if obj:
            return self.readonly_fields + ('identifier',)
        return self.readonly_fields


@admin.register(models.Organization)
class OrganizationAdmin(admin.ModelAdmin):
    inlines = [CollaboratorInline,]


@admin.register(models.PycswConfig)
class PycswConfigAdmin(admin.ModelAdmin):

    #def has_add_permission(self, request):
    #    return False

    def has_delete_permission(self, request, obj=None):
        return False

url = models.URLField()
    address = models.CharField(max_length=255, blank=True)
    city = models.CharField(max_length=50, blank=True)
    state_or_province = models.CharField(max_length=50, blank=True)
    postal_code = models.CharField(max_length=30, blank=True)
    country = models.CharField(max_length=50, blank=True)

    def __unicode__(self):
        return self.short_name


class Collaborator(models.Model):
    name = models.CharField(max_length=255)
    position = models.CharField(max_length=255)
    email = models.EmailField()
    organization = models.ForeignKey(Organization,
                                     related_name="collaborators")
    url = models.URLField(blank=True)
    phone = models.CharField(max_length=50, blank=True)
    fax = models.CharField(max_length=50, blank=True)
    hours_of_service = models.CharField(max_length=50, blank=True)
    contact_instructions = models.CharField(max_length=255, blank=True)

    def __unicode__(self):
        return "{}({})".format(self.name, self.organization.short_name)

class Record(models.Model):
    identifier = models.CharField(
        max_length=255, db_index=True, help_text="Maps to pycsw:Identifier")
    title = models.CharField(max_length=255, null=True,blank=True,
                             help_text='Maps to pycsw:Title')
    typename = models.CharField(