public String getInternalExtParam(String key) {
        if (internalExtParams == null) {
            return null;
        }
        return internalExtParams.get(key);
    }
@author Robert HG (254963746@qq.com) on 6/13/15.
lts-core/src/main/java/com/github/ltsopensource/core/domain/JobMeta.java