null binding definitions should be allowed with a warning

[jshook]

12:37:15.681 [scenarios:001] ERROR io.engineblock.script.Scenario - Non-Script error while running scenario:Error initializing activity 'sensors': null
java.lang.RuntimeException: Error initializing activity 'sensors': null
at io.engineblock.core.ActivityExecutor.startActivity(ActivityExecutor.java:98)
at io.engineblock.core.ScenarioController.run(ScenarioController.java:83)
at io.engineblock.core.ScenarioController.run(ScenarioController.java:89)
at io.engineblock.core.ScenarioController.run(ScenarioController.java:96)
at jdk.scripting.nashorn.scripts/jdk.nashorn.internal.scripts.Script$Recompilation$1$^eval_/0x00000008401b8c40.:program(:2)
at jdk.scripting.nashorn/jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:655)
at jdk.scripting.nashorn/jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:513)
at jdk.scripting.nashorn/jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:527)
at jdk.scripting.nashorn/jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:456)
at jdk.scripting.nashorn/jdk.nashorn.api.scripting.NashornScriptEngine$3.eval(NashornScriptEngine.java:517)
at java.scripting/javax.script.CompiledScript.eval(CompiledScript.java:103)
at io.engineblock.script.Scenario.run(Scenario.java:138)
at io.engineblock.script.Scenario.call(Scenario.java:171)
at io.engineblock.script.Scenario.call(Scenario.java:44)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.NullPointerException: null
at java.base/java.util.regex.Matcher.getTextLength(Matcher.java:1770)
at java.base/java.util.regex.Matcher.reset(Matcher.java:416)
at java.base/java.util.regex.Matcher.(Matcher.java:253)
at java.base/java.util.regex.Pattern.matcher(Pattern.java:1133)
at io.virtdata.core.CompatibilityFixups.fix(CompatibilityFixups.java:64)
at io.virtdata.core.CompatibilityFixups.fixup(CompatibilityFixups.java:53)
at io.virtdata.core.VirtData.getOptionalMapper(VirtData.java:82)
at io.virtdata.core.BindingsTemplate.resolveBindings(BindingsTemplate.java:103)
at io.virtdata.templates.StringBindingsTemplate.resolve(StringBindingsTemplate.java:34)
at io.engineblock.activitytypes.stdout.StdoutActivity.initOpSequencer(StdoutActivity.java:145)
at io.engineblock.activitytypes.stdout.StdoutActivity.initActivity(StdoutActivity.java:99)
at io.engineblock.core.ActivityExecutor.startActivity(ActivityExecutor.java:94)
... 17 common frames omitted

[jshook]

superseded by nosqlbench/nosqlbench#5