@AfterClass
    public static void destroy() {
        System.clearProperty(FileSandboxExtension.GREMLIN_SERVER_SANDBOX);
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-groovy/src/test/java/org/apache/tinkerpop/gremlin/groovy/jsr223/GremlinGroovyScriptEngineFileSandboxTest.java