public void applyConfig() {
            this.appliedConnConfig = new AppliedConnectorConfig(connConfig);
        }
@param connConfig the connector's configuration
@param targetState the connector's initial {@link TargetState}; may be {@code null} in which case the default initial target state
{@link TargetState#STARTED} will be used
connect/runtime/src/main/java/org/apache/kafka/connect/storage/MemoryConfigBackingStore.java