Class:
public class CollectionsInLightningCls 
{
    @AuraEnabled
    public static Map<String, Map<String, List<String>>> getPicklistValues(String objpicklistFieldsMap)
    {
        Map<String, List<String>> objPickmap = (Map<String, List<String>>)JSON.deserialize(objpicklistFieldsMap, Map<String, List<String>>.class);
        system.debug('objpickmap ' + objPickmap);
         
        Map<String, Map<String, List<String>>> objFieldPicklistMap = new Map<String, Map<String, List<String>>>();
        List<String> sobjectslist = new List<String>(objPickmap.keySet());
        Schema.DescribeSobjectResult[] results = Schema.describeSObjects(sobjectslist);
        Map<String, List<String>> fieldOptionsMap;
        system.debug('results---' + results);
        for(Schema.DescribeSObjectResult result : results)
        {
            fieldOptionsMap = new Map<String, List<String>>();
             system.debug('result123---' + result);
            Schema.sObjectType objType = result.getSObjectType();
             
            Schema.DescribeSObjectResult objDescribe = objType.getDescribe();
            map<String, Schema.SObjectField> fieldMap = objDescribe.fields.getMap();
            List<String> objFieldlist = objPickmap.get(result.getName());
            system.debug('objname ' + result.getName());
            system.debug('list of fields ' + objFieldlist);
            for(String fld : objFieldlist)
            {
                system.debug('fields ' + fld);
                List<String > allOpts = new list<String>();
                list<Schema.PicklistEntry> values =
                fieldMap.get(fld).getDescribe().getPickListValues();
                 
                for (Schema.PicklistEntry a : values)
                {
                    allOpts.add(a.getValue());
                }
                fieldOptionsMap.put(fld, allOpts);
            }
            
            objFieldPicklistMap.put(result.getName(), fieldOptionsMap);
        }
        return objFieldPicklistMap;
    }
    
    @AuraEnabled
    public static list<NA_Other_Existing_Loans__c> getExistingLoans(String AssessmentId)
    {
        list<NA_Other_Existing_Loans__c> otherExistingLoans = new list<NA_Other_Existing_Loans__c>();
        otherExistingLoans = [select id, Balance__c, End_Date__c, Financial_Institution__c, Needs_Assessment__c, Rate__c, Type_of_Loan__c 
                        from NA_Other_Existing_Loans__c where Needs_Assessment__c =: AssessmentId];
                        
        return otherExistingLoans;        
    }
    
    @AuraEnabled
    public static list<NA_Membership_Referral_Questions__c> getMembershipLoans(String AssessmentId)
    {
        list<NA_Membership_Referral_Questions__c> loans = new list<NA_Membership_Referral_Questions__c>();
        loans = [select id, Age__c, Name__c, Needs_Assessment__c, Want_to_Refer_Membership__c 
                        from NA_Membership_Referral_Questions__c where Needs_Assessment__c =: AssessmentId];
                        
        return loans;        
    }
    
    @AuraEnabled
    public static list<NA_Deposit__c> GetDepositData(String AssessmentId)
    {
        list<NA_Deposit__c> deposits = new list<NA_Deposit__c>();
        deposits = [select id, Balance__c, Financial_Instituition__c, Needs_Assessment__c, Rate__c, Type__c 
                        from NA_Deposit__c where Needs_Assessment__c =: AssessmentId];
                        
        return deposits;        
    }
    
    
    @AuraEnabled    
    public static Map<String, List<KeyValuePairModelInt>> getYearPickList()
    {   
        Map<String, List<KeyValuePairModelInt>> options = new Map<String, List<KeyValuePairModelInt>>();
        KeyValuePairModelInt pair = new KeyValuePairModelInt();
        List<KeyValuePairModelInt> lstPair = new List<KeyValuePairModelInt>();
        pair.Text = '--None--';
        pair.Value = 0;
                
        lstPair.add(pair);
        
        for (Integer i = System.Today().year() + 1; i < System.Today().year() + 31; i++) 
        {
            pair = new KeyValuePairModelInt();
            pair.Text = string.valueof(i);
            pair.Value = i;
            lstPair.add(pair);            
        }
        options.put('data', lstPair);
        return options;        
    }
    
        
    public class KeyValuePairModelInt
    {
        @AuraEnabled    
        public string Text {get;set;}
        @AuraEnabled    
        public Integer Value {get;set;}
        
    } 
}

============================
Test Class:
@isTest

private class CollectionsInLightningClsTest
{
    
    static void SetUp(){
        test.StartTest();
    }

    static void TearDown(){
        test.StopTest();
    }
    
    // Test Method: getPicklistValues
    public static testmethod void Test_getPicklistValues(){
        SetUp();
        string objpicklistfieldsmap = '';
        // TODO : Change following Assert Statement
        Needs_Assesment__c NC;
        NC = new Needs_Assesment__c();
        
        NC.Home_Improvement__c = 'Prefer Not to Answer';
        NC.Home_Improvement_Timeframe__c='3-6 months';
        NC.Home_Improvement_Plan__c= 'Finance';
        NC.College__c= 'Yes';
        NC.College_Timeframe__c= '3-6 months';
        NC.College_Plan__c='Both';
        NC.Medical__c='Prefer Not to Answer';
        NC.Medical_Timeframe__c='3-6 months';
        NC.Medical_Plan__c='Both';
        NC.Purchase_RV_Boat__c='Yes';
        NC.Purchase_RV_Boat_Timeframe__c='3-6 months';
        NC.Purchase_RV_Boat_Plan__c='Savings';
        NC.Retirement_New__c='Yes';
        NC.Retirement_Timeframe__c='3-6 months';
        NC.Retirement_Plan__c='Savings';
        NC.Travel__c= 'Yes';
        NC.Travel_Timeframe__c='3-6 months';
        NC.Travel_Plan__c='Savings';
        NC.Life_Events__c='Prefer Not to Answer';
        NC.Life_Events_Timeframe__c='3-6 months';
        NC.Life_Events_Plan__c='Finance';
        NC.Other__c='Yes';
        NC.Other_Timeframe__c='3-6 months';
        NC.Other_Plan__c= 'Savings';   
        insert NC;
        
        System.Assert(CollectionsInLightningCls.getPicklistValues(objpicklistfieldsmap) != null);
        TearDown();
    }
    // Test Method: getExistingLoans
    public static testmethod void Test_getExistingLoans(){
        SetUp();
        string assessmentid = '';
        // TODO : Change following Assert Statement
        System.Assert(CollectionsInLightningCls.getExistingLoans(assessmentid) != null);
        TearDown();
    }
    // Test Method: getMembershipLoans
    public static testmethod void Test_getMembershipLoans(){
        SetUp();
        string assessmentid = '';
        // TODO : Change following Assert Statement
        System.Assert(CollectionsInLightningCls.getMembershipLoans(assessmentid) != null);
        TearDown();
    }
    // Test Method: GetDepositData
    public static testmethod void Test_GetDepositData(){
        SetUp();
        string assessmentid = '';
        // TODO : Change following Assert Statement
        System.Assert(CollectionsInLightningCls.GetDepositData(assessmentid) != null);
        TearDown();
    }
    // Test Method: getYearPickList
    public static testmethod void Test_getYearPickList(){
        SetUp();
        // TODO : Change following Assert Statement
        System.Assert(CollectionsInLightningCls.getYearPickList() != null);
        TearDown();
    }
}