Added LeadQueryRepository.cls with 2 sample methods

Author: jongpie

src/classes/LeadQueryRepository.cls

@@ -0,0 +1,23 @@
+public class LeadQueryRepository {
+
+    public static Lead getLeadById(Id leadId) {
+        // Created a string for your where clause
+        String whereClause = 'WHERE Id = :leadId';
+        // Created a new instance of QueryGenerator, using a field set and your where clause
+        String query = new QueryGenerator(SObjectType.Lead.FieldSets.MyFieldSet).buildQuery(whereClause);
+
+        // Database.query returns generic SObjects, so cast it to the desired SObject type & return it
+        return (Lead)Database.query(query);
+    }
+
+    public static List<Lead> getLeadsByStatus(String status) {
+        // Created a string for your where clause
+        String whereClause = 'WHERE Status = :status';
+        // Created a new instance of QueryGenerator, using a field set and your where clause
+        String query = new QueryGenerator(SObjectType.Lead.FieldSets.MyFieldSet).buildQuery(whereClause);
+
+        // Database.query returns generic SObjects, so cast it to the desired SObject type & return it
+        return (List<Lead>)Database.query(query);
+    }
+
+}

src/classes/LeadQueryRepository.cls-meta.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
+    <apiVersion>38.0</apiVersion>
+    <status>Active</status>
+</ApexClass>