Jmeter - Inline evaluation error in Beanshell Assertion

I am getting this error, and cannot figure out what wrong I am doing:

Error invoking bsh method: eval In file: inline evaluation of: ``import java.util.Set; import java.util.Map; import java.util.List;  try { //   Map . . . '' Encountered "String" at line 17, column 9.

This is the code that I am using:

import java.util.Set;
import java.util.Map;
import java.util.List;

try
{
//  Map<String,List<String>> map = new HashMap<String,List<String>>();

//  map = vars.getObject("headerMap");
    boolean isHeaderValid = false;
    
//  String apiKeySent = "${x_api_key}"
//  String clientIdSent = "${X_IBM_Client_id}"
//  String clientSecretSent = "${X_IBM_Client_Secret}"

    String apiKeySent = vars.get("x_api_key")
    String clientIdSent = vars.get("X_Client_id")
    String clientSecretSent = vars.get("X_Client_Secret")

    log.info("apiKeySent: " + vars.get("x_api_key"))
    log.info("clientIdSent: " + vars.get("X_Client_id"))
    log.info("clientSecretSent: " + vars.get("X_Client_Secret"))
    
    if(apiKeySent != "")
    {
        apiKeyRec = vars.get("apiKeyRec")
        isHeaderValid = apiKeySent.equals(apiKeyRec)
    }
    Failure = isHeaderValid
}
catch(Exception e)
{
    log.debug("Error in verification: ",e)
}

Could anyone please help me in figuring this out? Have been stuck at this for ages.