public Grok(CommandBuilder builder, Config config, Command parent, Command child, MorphlineContext context) {
super(builder, config, parent, child, context);
GrokDictionaries dict = new GrokDictionaries(config, getConfigs());
Config exprConfig = getConfigs().getConfig(config, "expressions", ConfigFactory.empty());
for (Map.Entry<String, Object> entry : new Configs().getEntrySet(exprConfig)) {
String expr = entry.getValue().toString();
this.regexes.put(entry.getKey(), dict.compileExpression(expr).matcher(""));
}
this.firstKey = (regexes.size() == 0 ? null : regexes.entrySet().iterator().next().getKey());