assert fieldName == "input" || fieldName == "output";
assert fieldName == "inputChannel" || fieldName == "outputChannel";
    Channel[] getIOFields (String fieldName)    {        assert fieldName == "input" || fieldName == "output";        Channel fieldsInstance [] = null;        try            {                Class thisClass = this.getClass ();                assert thisClass != null;                Field ioField;                ioField  = thisClass.getField (fieldName);                Object fieldValue = ioField.get (this);                if (ioField.getType ().isArray ())                    {                        fieldsInstance = (Channel []) fieldValue;                    } else {                        fieldsInstance = new Channel [1];                        fieldsInstance [0] = (Channel) fieldValue;                        if (fieldsInstance [0] == null) fieldsInstance = null;                    }            }        catch (NoSuchFieldException noError)            {                // do not do anything here, this is NOT an error!            }        catch (Throwable error)            {                // this is all the other errors:                error.getClass ();                assert false : error.toString ();            }        return fieldsInstance;    }