question: return the spark user for authenticating sasl connections . concode_field_sep ConcurrentHashMap<String,String> shuffleSecretMap concode_elem_sep Logger logger concode_elem_sep String SPARK_SASL_USER concode_field_sep String getSecretKey concode_elem_sep void registerApp concode_elem_sep void registerApp concode_elem_sep void unregisterApp
target: String function ( String arg0 ) { return SPARK_SASL_USER ; }