---
title: "writeAttributeNullableOctetString(withValue:expectedValueInterval:params:)"
framework: matter
role: symbol
role_heading: Instance Method
path: "matter/mtrclusterunittesting/writeattributenullableoctetstring(withvalue:expectedvalueinterval:params:)"
---

# writeAttributeNullableOctetString(withValue:expectedValueInterval:params:)

## Declaration

```swift
func writeAttributeNullableOctetString(withValue dataValueDictionary: [String : Any], expectedValueInterval expectedValueIntervalMs: NSNumber, params: MTRWriteParams?)
```