     private func willWrite(uuid: BluetoothUUID, handle: UInt16, value: Data, newValue: Data) async -> ATTError? {
         let request = GATTWriteRequest(
             central: central,
-            maximumUpdateValueLength: await maximumUpdateValueLength(),
+            maximumUpdateValueLength: await maximumUpdateValueLength,
             uuid: uuid,
             handle: handle,
             value: value,

    private func didWrite(uuid: BluetoothUUID, handle: UInt16, value: Data) async {
        let confirmation = GATTWriteConfirmation(
            central: central,
            maximumUpdateValueLength: await maximumUpdateValueLength(),
            uuid: uuid,
            handle: handle,
            value: value

    private func willRead(uuid: BluetoothUUID, handle: UInt16, value: Data, offset: Int) async -> ATTError? {
        let request = GATTReadRequest(
            central: central,
            maximumUpdateValueLength: await maximumUpdateValueLength,
            uuid: uuid,
            handle: handle,
            value: value,
