Remove uses of isKey()

test/gtest_feature_imu.cpp

@@ -124,9 +124,6 @@ TEST_F(FeatureImu_test, check_frame)
     origin_frame->getTimeStamp(ts);
 
     ASSERT_NEAR(t.get(), ts.get(), wolf::Constants::EPS_SMALL) << "t != ts \t t=" << t << "\t ts=" << ts << std::endl;
-    ASSERT_TRUE(origin_frame->isKey());
-    ASSERT_TRUE(last_frame->isKey());
-    ASSERT_TRUE(left_frame->isKey());
 
     wolf::StateBlockPtr origin_pptr, origin_optr, origin_vptr, left_pptr, left_optr, left_vptr;
     origin_pptr = origin_frame->getP();