### Question:
AbbreviatedData extends OFDElement implements Cloneable { @Override public String toString() { if (dataQueue.size() == 0) { throw new IllegalArgumentException("AbbreviatedData 不能为空"); } StringBuilder dataBuilder = new StringBuilder(); int cnt = 0; for (String[] operatorItem : dataQueue) { cnt++; if (cnt != 1) { dataBuilder.append(" "); } for (String item : operatorItem) { dataBuilder.append(item); } } return dataBuilder.toString(); } AbbreviatedData(Element proxy);  AbbreviatedData(); static LinkedList<String[]> parse(String txt); AbbreviatedData flush(); AbbreviatedData defineStart(double x, double y); AbbreviatedData s(ST_Pos start); AbbreviatedData S(double x, double y); AbbreviatedData moveTo(double x, double y); AbbreviatedData M(double x, double y); AbbreviatedData M(ST_Pos target); AbbreviatedData lineTo(double x, double y); AbbreviatedData L(double x, double y); AbbreviatedData L(ST_Pos p); AbbreviatedData quadraticBezier(double x1, double y1,
                                           double x2, double y2); AbbreviatedData Q(double x1, double y1,
                             double x2, double y2); AbbreviatedData Q(ST_Pos control,
                             ST_Pos target); AbbreviatedData cubicBezier(double x1, double y1,
                                       double x2, double y2,
                                       double x3, double y3); AbbreviatedData B(double x1, double y1,
                             double x2, double y2,
                             double x3, double y3); AbbreviatedData B(ST_Pos control1,
                             ST_Pos control2,
                             ST_Pos target); AbbreviatedData arc(double rx, double ry,
                               double angle, int large,
                               int sweep, double x, double y); AbbreviatedData A(double rx, double ry,
                             double angle, int large,
                             int sweep, double x, double y); AbbreviatedData A(double rx, double ry,
                             double angle, int large,
                             int sweep, ST_Pos target); AbbreviatedData close(); AbbreviatedData C(); AbbreviatedData undo(); @Override String toString(); @Override AbbreviatedData clone();  }### Answer:
@Test public void gen(){ AbbreviatedData data = abbreviatedDataCase(); System.out.println(data); assertTrue("M 50 50 L 250 50 L 250 200 L 50 200 C".equals(data.toString())); }