diff --git a/build.gradle b/build.gradle
index 145d1e4..5666744 100644
--- a/build.gradle
+++ b/build.gradle
@@ -21,8 +21,7 @@ dependencies {
     compile 'com.google.guava:guava:+',
             'org.apache.commons:commons-lang3:+',
             'ch.qos.logback:logback-classic:+',
-            'io.javaslang:javaslang:+',
-            'com.github.Vyacheslav-Lapin:Hegel:master-SNAPSHOT' //https://github.com/Vyacheslav-Lapin/Hegel.git
+            'io.javaslang:javaslang:+'
 
     compileOnly 'org.projectlombok:lombok:+',
             'edu.washington.cs.types.checker:checker-framework:+'
diff --git a/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java b/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java
index 14cfc0d..93db1c0 100644
--- a/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java
+++ b/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java
@@ -1,9 +1,14 @@
 package lambda.part1.exercise;
 
+import com.google.common.base.Optional;
+import com.google.common.base.Predicate;
+import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
 import data.Person;
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
+import java.util.Comparator;
 import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
@@ -19,7 +24,12 @@ void sortPersonsByAge() {
                 new Person("name 2", "lastName 1", 30)
         };
 
-        // TODO use Arrays.sort
+        Arrays.sort(persons, new Comparator<Person>() {
+            @Override
+            public int compare(Person o1, Person o2) {
+                return o1.getAge() - o2.getAge();
+            }
+        });
 
         assertArrayEquals(persons, new Person[]{
                 new Person("name 3", "lastName 3", 20),
@@ -38,7 +48,16 @@ void findFirstWithAge30() {
 
         Person person = null;
 
-        // TODO use FluentIterable
+        final Optional<Person> personOptional =
+                FluentIterable.from(persons)
+                        .firstMatch(new Predicate<Person>() {
+                            public boolean apply(Person p) {
+                                return p.getAge() == 30;
+                            }
+                        });
+
+        if (personOptional.isPresent())
+            person = personOptional.get();
 
         assertEquals(person, new Person("name 1", "lastName 2", 30));
     }
diff --git a/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java b/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java
index 8f47d34..23527cd 100644
--- a/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java
+++ b/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java
@@ -4,7 +4,9 @@
 import data.Person;
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
 import java.util.List;
+import java.util.Optional;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -18,7 +20,7 @@ void sortPersonsByAge() {
                 new Person("name 2", "lastName 1", 30)
         };
 
-        // TODO use Arrays.sort
+        Arrays.sort(persons, (o1, o2) -> o1.getAge() - o2.getAge());
 
         assertArrayEquals(persons, new Person[]{
                 new Person("name 3", "lastName 3", 20),
@@ -37,7 +39,11 @@ void findFirstWithAge30() {
 
         Person person = null;
 
-        // TODO use FluentIterable
+        final Optional<Person> personOptional =
+                persons.stream().filter(p -> p.getAge() == 30).findFirst();
+
+        if (personOptional.isPresent())
+            person = personOptional.get();
 
         assertEquals(person, new Person("name 1", "lastName 2", 30));
     }
diff --git a/src/test/java/lambda/part3/exercise/Mapping.java b/src/test/java/lambda/part3/exercise/Mapping.java
index 308faa8..b674f90 100644
--- a/src/test/java/lambda/part3/exercise/Mapping.java
+++ b/src/test/java/lambda/part3/exercise/Mapping.java
@@ -13,6 +13,7 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+
 class Mapping {
 
     private static class MapHelper<T> {
@@ -29,8 +30,11 @@ public List<T> getList() {
         // [T] -> (T -> R) -> [R]
         // [T1, T2, T3] -> (T -> R) -> [R1, R2, R3]
         public <R> MapHelper<R> map(Function<T, R> f) {
-            // TODO
-            throw new UnsupportedOperationException();
+            final List<R> result = new ArrayList<R>();
+            list.forEach((T t) ->
+                    result.add(f.apply(t)));
+
+            return new MapHelper<R>(result);
         }
 
         // [T] -> (T -> [R]) -> [R]
@@ -73,12 +77,10 @@ void mapping() {
 
         final List<Employee> mappedEmployees =
                 new MapHelper<>(employees)
-                /*
-                .map(TODO) // change name to John .map(e -> e.withPerson(e.getPerson().withFirstName("John")))
-                .map(TODO) // add 1 year to experience duration .map(e -> e.withJobHistory(addOneYear(e.getJobHistory())))
-                .map(TODO) // replace qa with QA
-                * */
-                .getList();
+                        .map(employee -> employee.withPerson(employee.getPerson().withFirstName("John")))
+                        .map(employee -> employee.withJobHistory(addOneYear(employee.getJobHistory())))
+                        .map(employee -> employee.withJobHistory(replaseQA(employee.getJobHistory())))
+                        .getList();
 
         final List<Employee> expectedResult =
                 Arrays.asList(
@@ -105,6 +107,17 @@ void mapping() {
         assertEquals(mappedEmployees, expectedResult);
     }
 
+    private List<JobHistoryEntry> replaseQA(List<JobHistoryEntry> jobHistory) {
+        MapHelper<JobHistoryEntry> jhem = new MapHelper<>(jobHistory);
+        return jhem.map(entry -> entry.withPosition(entry.getPosition()
+                .replace("qa", "QA"))).getList();
+    }
+
+    private List<JobHistoryEntry> addOneYear(List<JobHistoryEntry> jobHistory) {
+        MapHelper<JobHistoryEntry> jhem = new MapHelper<>(jobHistory);
+        return jhem.map(entry -> entry.withDuration(entry.getDuration() + 1)).getList();
+    }
+
 
     private static class LazyMapHelper<T, R> {