Hi and thanks in Advance.  I was able to write a test code for my class, but need help.  This provides 5% coverage.

Class:
global with sharing class TMWSendOrderService 
{
    public class OrderResponse 
    {
        string OrderNumber;
        List<string> Comments = new List<string>();
        List<string> Errors = new List<string>();
        string CaseNumber;
    }
  
  public class FuelOrdered 
    {
    string Type;
    integer Amount;
  }
    
    public class TmwOrder 
    {
        string CaseNumber;
        Date DeliveryDate;
        string DeliveryTimeframe;
        string CompanyCode;
        string Origin;
    List<FuelOrdered> FuelList = new List<FuelOrdered>();
    List<string> ErrorsFound = new List<string>();
    }
  
    webservice static String SendToTmw(string cid) 
    {
    system.debug('cid: ' + cid);
        return SendOrderToTmw(cid);
    }
  
    private static string SendOrderToTmw(string cid)
    {

        if(String.isBlank(cid))
            return 'INVALID_PARAMETERS';
        
        // get list of cases that have not yet been sent to TMW and have a valid quantity
    List<Case> sfCases = [ SELECT Id, AccountId, CaseNumber, Origin, 
        RQ_Delivery_Date__c, RQ_Delivery_Timeframe__c, 
        Fuel1_Requested_Type__c, Fuel1_Requested_Amount__c, 
        Fuel2_Requested_Type__c, Fuel2_Requested_Amount__c, 
        Fuel3_Requested_Type__c, Fuel3_Requested_Amount__c, 
        Fuel4_Requested_Type__c, Fuel4_Requested_Amount__c
      FROM Case WHERE id = :cid 
      AND TMW_Order_Num__c = '' //AND SendtoTMW__c = false 
      AND ( 
        Fuel1_Requested_Amount__c > 0 OR Fuel2_Requested_Amount__c > 0 
                OR Fuel3_Requested_Amount__c > 0 OR Fuel4_Requested_Amount__c > 0 
            ) ]; 
        // Instantiate a new http object.  Create a list of cases and send to REST service
        if(sfCases.size() == 0)
            return 'This case requires: valid quantity, requested delivery time and timeframe, and cannot be a resubmission.';
        Http h = new Http();
        HttpRequest req = new HttpRequest();
        Case sfCase = sfCases[0];
    // get company  code from translation table
    string companyCode = 
        [  
          SELECT Surrogate_ID__c FROM Translation_Table__c 
          WHERE IntegratedSite__c = :sfCase.AccountId LIMIT 1
        ].Surrogate_ID__c.replace('TMW-','');
        // populate case
        TmwOrder tmwOrder = new TmwOrder();
        tmwOrder.CaseNumber = sfCase.casenumber;
        tmwOrder.DeliveryDate = sfCase.RQ_Delivery_Date__c;
        tmwOrder.DeliveryTimeframe = sfCase.RQ_Delivery_Timeframe__c;
        tmwOrder.CompanyCode = companyCode;
        tmwOrder.Origin = sfCase.Origin;
        FuelOrdered item = new FuelOrdered();
        // create FuelOrdered list from requested types/amounts
        item.Type = sfCase.Fuel1_Requested_Type__c;
        item.Amount = Integer.valueOf(sfCase.Fuel1_Requested_Amount__c);
        if (item.Amount > 0) tmwOrder.FuelList.Add(item);
        item = new FuelOrdered();
        item.Type = sfCase.Fuel2_Requested_Type__c;
        item.Amount = Integer.valueOf(sfCase.Fuel2_Requested_Amount__c);
        if (item.Amount > 0) tmwOrder.FuelList.Add(item);
        item = new FuelOrdered();
        item.Type = sfCase.Fuel3_Requested_Type__c;
        item.Amount = Integer.valueOf(sfCase.Fuel3_Requested_Amount__c);
        if (item.Amount > 0) tmwOrder.FuelList.Add(item);
        item = new FuelOrdered();
        item.Type = sfCase.Fuel4_Requested_Type__c;
        item.Amount = Integer.valueOf(sfCase.Fuel4_Requested_Amount__c);
        if (item.Amount > 0) tmwOrder.FuelList.Add(item);
        string postString = JSON.serialize(tmwOrder);
        req.setBody(postString);
        req.setEndpoint('http://dev-tmw.sunocolp.com/api/CreateTMWOrder');
        req.setHeader('content-type','application/json');
        req.setTimeout(60000);
        req.setMethod('POST');
        //req.setCompressed(true);
        // Send the request, and return a response
        HttpResponse res = h.send(req);
        string bod = res.getBody();
        system.debug(bod);
        OrderResponse rsp = (OrderResponse)JSON.deserialize(bod, OrderResponse.class);
        system.debug('order response: ' + rsp);
        Case newCase;
        if (rsp.OrderNumber != null && rsp.OrderNumber !='')
        {
            // If Order was created, add order # to the case
            newCase = 
      [  
        Select Id, TMW_Order_Num__c, SFtoTMWSent__c, SendtoTMW__c  
                FROM Case 
                WHERE CaseNumber = :rsp.CaseNumber
            ];
            newCase.TMW_Order_Num__c = rsp.OrderNumber;
            newCase.SendtoTMW__c = true;
            newCase.SFtoTMWSent__c = date.today();
            update newCase;
        }
        else
        {
            // No order # was returned.  Mark case as sent to TMW.
            newCase = 
            [  
                 SELECT Id, SFtoTMWSent__c, SendtoTMW__c  
                 FROM Case 
                 WHERE CaseNumber = :rsp.CaseNumber
            ];
            newCase.SendtoTMW__c = true;
            newCase.SFtoTMWSent__c = date.today();
            update newCase;
        }
        // add case comments (if any)
        for (Integer i = 0; i < rsp.Comments.size(); i++)
        {
            CaseComment com = new CaseComment();
            com.ParentId = newCase.id;
            com.CommentBody = rsp.Comments[i];
            insert com;
        }        
        return 'Order submitted successfully!';
    }
}
---------------------------
Test Class:
@isTest
 
private class TMWSendOrderService_Test{
 
  @testSetup
 
  static void setupTestData(){
 
    test.startTest();
 
    Translation_Table__c translation_table_Obj = new Translation_Table__c(Integration_Status__c = false);
 
    Insert translation_table_Obj; 
 
    test.stopTest();
 
  }
 
   static testMethod void test_TmwOrder(){
 
    List<Translation_Table__c> translation_table_Obj  =  [SELECT Integration_Status__c, Name from Translation_Table__c];
 
    System.assertEquals(true,translation_table_Obj.size()>0);
 
    TMWSendOrderService obj01 = new TMWSendOrderService();
 
    TMWSendOrderService.OrderResponse obj11 = new TMWSendOrderService.OrderResponse();
 
    TMWSendOrderService.FuelOrdered obj21 = new TMWSendOrderService.FuelOrdered();
 
    TMWSendOrderService.TmwOrder obj31 = new TMWSendOrderService.TmwOrder();
 
  }
 
}