@Test
    public void shouldOpenViaPropertiesFileConfig() throws IOException {
        final File scriptFile1 = TestSupport.generateTempFileFromResource(DefaultScriptCustomizerTest.class, "script-customizer-1.groovy", ".groovy");
        final File scriptFile2 = TestSupport.generateTempFileFromResource(DefaultScriptCustomizerTest.class, "script-customizer-2.groovy", ".groovy");
        final List<File> files = new ArrayList<>();
        files.add(scriptFile1);
        files.add(scriptFile2);
        final ScriptCustomizer scripts = new DefaultScriptCustomizer(files);

        final Collection<List<String>> linesInFiles = scripts.getScripts();
        final String scriptCombined = linesInFiles.stream().flatMap(Collection::stream).map(s -> s + System.lineSeparator()).reduce("", String::concat);
        assertEquals("x = 1 + 1" +  System.lineSeparator() +
                     "y = 10 * x" +   System.lineSeparator() +
                     "z = 1 + x + y" +  System.lineSeparator() +
                     "l = g.V(z).out()" +  System.lineSeparator() +
                     "        .group().by('name')" + System.lineSeparator(), scriptCombined);

    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/jsr223/DefaultScriptCustomizerTest.java