How to write Test Class for dependent picklist methods?
  
 @AuraEnabled
    public static List<String> getDepStates(String objectType, String parentField, String childField,String search){    
        List<String> optionStates = new List<String>();
        PicklistFieldController controller = new PicklistFieldController();
        Map<String,List<String>> valueMap = PicklistFieldController.getDependentOptionsImpl(objectType,parentField,childField);
        for(String contr : valueMap.keySet()){
           // System.debug('CONTROLLING FIELD : ' + contr);
            //System.debug('DEPENDENT VALUES ...  : ' + valueMap.get(contr));
            if(search==contr){
                optionStates=valueMap.get(contr);
            }
        }
        return optionStates;
    }
    @AuraEnabled
    public static List<String> getPickList(String field,String objectName){    
        List<String> lstPickvals=new List<String>();
        Schema.SObjectType targetType = Schema.getGlobalDescribe().get(objectName);
        Sobject Object_name = targetType.newSObject();
        Schema.sObjectType sobject_type = Object_name.getSObjectType(); 
        Schema.DescribeSObjectResult sobject_describe = sobject_type.getDescribe(); 
        Map<String, Schema.SObjectField> field_map = sobject_describe.fields.getMap(); 
        List<Schema.PicklistEntry> pick_list_values = field_map.get(field).getDescribe().getPickListValues(); 
        for (Schema.PicklistEntry a : pick_list_values) { //for all values in the picklist list
            lstPickvals.add(a.getValue());//add the value  to our final list
        }        
        return lstPickvals;
    }
   
}