void test_create()
 {
     TS_ASSERT_EQUALS(0.0, menvelope->getDoubleAttr("spdiameter"));
     menvelope->setDoubleAttr("spdiameter", 13.0);
     TS_ASSERT_EQUALS(13.0, menvelope->getDoubleAttr("spdiameter"));
     PDFEnvelopePtr e1 = menvelope->create();
     TS_ASSERT_EQUALS(0.0, e1->getDoubleAttr("spdiameter"));
 }
 void test_copy()
 {
     menvelope->setDoubleAttr("spdiameter", 13.0);
     TS_ASSERT_EQUALS(13.0, menvelope->getDoubleAttr("spdiameter"));
     PDFEnvelopePtr e1 = menvelope->clone();
     TS_ASSERT_EQUALS(13.0, e1->getDoubleAttr("spdiameter"));
 }