Constant WRITE_FIELD_VALUES 

pub const WRITE_FIELD_VALUES: &str = "mutation($field0:UpdateProjectV2ItemFieldValueInput!,$field1:UpdateProjectV2ItemFieldValueInput!,$field2:UpdateProjectV2ItemFieldValueInput!,$field3:UpdateProjectV2ItemFieldValueInput!,$field4:UpdateProjectV2ItemFieldValueInput!,$field5:UpdateProjectV2ItemFieldValueInput!,$field6:UpdateProjectV2ItemFieldValueInput!,$field7:UpdateProjectV2ItemFieldValueInput!,$field8:UpdateProjectV2ItemFieldValueInput!,$field9:UpdateProjectV2ItemFieldValueInput!,$field10:UpdateProjectV2ItemFieldValueInput!,$send0:Boolean!,$send1:Boolean!,$send2:Boolean!,$send3:Boolean!,$send4:Boolean!,$send5:Boolean!,$send6:Boolean!,$send7:Boolean!,$send8:Boolean!,$send9:Boolean!,$send10:Boolean!){ field0:updateProjectV2ItemFieldValue(input:$field0) @include(if:$send0){projectV2Item{id}} field1:updateProjectV2ItemFieldValue(input:$field1) @include(if:$send1){projectV2Item{id}} field2:updateProjectV2ItemFieldValue(input:$field2) @include(if:$send2){projectV2Item{id}} field3:updateProjectV2ItemFieldValue(input:$field3) @include(if:$send3){projectV2Item{id}} field4:updateProjectV2ItemFieldValue(input:$field4) @include(if:$send4){projectV2Item{id}} field5:updateProjectV2ItemFieldValue(input:$field5) @include(if:$send5){projectV2Item{id}} field6:updateProjectV2ItemFieldValue(input:$field6) @include(if:$send6){projectV2Item{id}} field7:updateProjectV2ItemFieldValue(input:$field7) @include(if:$send7){projectV2Item{id}} field8:updateProjectV2ItemFieldValue(input:$field8) @include(if:$send8){projectV2Item{id}} field9:updateProjectV2ItemFieldValue(input:$field9) @include(if:$send9){projectV2Item{id}} field10:updateProjectV2ItemFieldValue(input:$field10) @include(if:$send10){projectV2Item{id}}}";

Up to MUTATION_BATCH board field values a copy writes on the items it created, each on its own item, in one ordered request.