Dynamics 365 Multi-table lookups

public Guid CreatePolymorphicLookup(string prefix, string displayName, string schemaName, string referencingEntity, string[] referencedEntities, string solutionUniqueName)
        {
            var label = new LocalizedLabel()
            {
                Label = displayName,
                LanguageCode = languageCode
            };

            var relations = new OneToManyRelationshipMetadata[referencedEntities.Length];
            for (var i = 0; i < referencedEntities.Length; i++)
            {
                var referencedEntity = referencedEntities[i];

                relations[i] = new OneToManyRelationshipMetadata
                {
                    SchemaName = $"{prefix}{referencingEntity}_{referencedEntity}_{schemaName}",
                    ReferencedEntity = referencedEntity,
                    ReferencingEntity = referencingEntity
                };

                if (relations[i].SchemaName.Length > 100)
                {
                    relations[i].SchemaName = relations[i].SchemaName.Substring(0, 100);
                }
            }

            var request = new OrganizationRequest
            {
                RequestName = "CreatePolymorphicLookupAttribute",
                Parameters =
                {
                    {"OneToManyRelationships", relations },
                    {
                        "Lookup", new LookupAttributeMetadata()
                        {
                            DisplayName = new Label(label, new LocalizedLabel[] {label}) ,
                            SchemaName = schemaName
                        }
                    },
                    {
                        "SolutionUniqueName", solutionUniqueName}
                }
            };

            var response = _service.Execute(request);

            return new Guid(response.Results["AttributeId"].ToString());
        }