Add tests for GetRequiredNamespaces function in Model class

Tests/CPP_Bindings/Source/Model.cpp

@@ -175,4 +175,47 @@ namespace Lib3MF
 		ASSERT_EQ(oldID, newId);
 	}
 
+	TEST_F(Model, GetRequiredNamespaces_NoExtensions_IsEmpty)
+	{
+		auto requiredNamespaces = m_pModel->GetRequiredNameSpaces();
+		ASSERT_TRUE(requiredNamespaces);
+		EXPECT_EQ(requiredNamespaces->Count(), 0u);
+	}
+
+	TEST_F(Model, GetRequiredNamespaces_BeamLatticeExtension_ContainsBeamLattice)
+	{
+		auto model = wrapper->CreateModel(); // create a new model to avoid interference with other tests
+		auto mesh = model->AddMeshObject();
+		auto beamLattice = mesh->BeamLattice();
+
+		ASSERT_TRUE(model);
+		ASSERT_TRUE(mesh);
+		ASSERT_TRUE(beamLattice);
+
+		sPosition p;
+		p.m_Coordinates[0] = 0;
+		p.m_Coordinates[1] = 0;
+		p.m_Coordinates[2] = 0;
+		mesh->AddVertex(p);
+
+		p.m_Coordinates[1] = 1;
+		mesh->AddVertex(p);
+
+		p.m_Coordinates[2] = 1;
+		mesh->AddVertex(p);
+
+		sBeam beam;
+		beam.m_Radii[0] = 1.0;
+		beam.m_Radii[1] = 1.0;
+		beam.m_Indices[0] = 0;
+		beam.m_Indices[1] = 1;
+		beamLattice->AddBeam(beam);
+
+		auto requiredNamespaces = model->GetRequiredNameSpaces();
+		ASSERT_TRUE(requiredNamespaces);
+		EXPECT_EQ(requiredNamespaces->Count(), 1u);
+		EXPECT_EQ(requiredNamespaces->MoveNext(), true);
+		EXPECT_EQ(requiredNamespaces->GetCurrent(), "http://schemas.microsoft.com/3dmanufacturing/beamlattice/2017/02");
+		EXPECT_EQ(requiredNamespaces->MoveNext(), false);
+	}
 }