     var str = ""
     for _x in x.map({ dataFormatter.string(from: NSNumber(value: $0)) ?? "0" }) {
         if !str.isEmpty && _x.first != "-" {
-            " ".write(to: &str)
+            str.append(" ")
         }
         _x.write(to: &str)
     }

        }
        
        if self.isClosed {
            "z".write(to: &data)
        }
    }
    

    command?.write(to: &result)
    let dataStr = getDataString(x)
    if result.isEmpty && !dataStr.isEmpty && dataStr.first != "-" {
        result.append(" ")
    }
    dataStr.write(to: &result)
    return result
