NativeConverter.setSubstitutionChars(converterHandle,null,0);
ec = NativeConverter.setSubstitutionModeByteToChar(converterHandle, false); } if(ec> ErrorCode.U_ZERO_ERROR){ throw new IllegalArgumentException(ErrorCode.getErrorName(ec));
    public final void setSubstitutionMode(boolean doSub) {        if(doSub){            NativeConverter.setSubstitutionChars(converterHandle,subChars,subChars.length);        }else{            NativeConverter.setSubstitutionChars(converterHandle,null,0);        }    }