private PlantUmlDiagram createDiagram(List<String> rawDiagramLines) {
        List<String> diagramLines = filterOutComments(rawDiagramLines);
        Set<PlantUmlComponent> components = parseComponents(diagramLines);
        PlantUmlComponents plantUmlComponents = new PlantUmlComponents(components);

        List<ParsedDependency> dependencies = parseDependencies(plantUmlComponents, diagramLines);

        return new PlantUmlDiagram.Builder(plantUmlComponents)
                .withDependencies(dependencies)
                .build();
    }
@Test
    public void ignores_components_that_are_not_yet_defined() {
        File file = TestDiagram.in(temporaryFolder)
                .dependencyFrom("[NotYetDefined]").to("[AlsoNotYetDefined]")
                .write();

        PlantUmlDiagram diagram = createDiagram(file);

        assertThat(diagram.getComponentsWithAlias()).isEmpty();
    }