diff --git a/src/main/java/com/github/cleanddd/model/Course.java b/src/main/java/com/github/cleanddd/model/Course.java
index 45faf74..71232c7 100644
--- a/src/main/java/com/github/cleanddd/model/Course.java
+++ b/src/main/java/com/github/cleanddd/model/Course.java
@@ -37,7 +37,7 @@ public class Course {
         return newCourse().numberOfStudents(numberOfStudents.get() + 1).build();
     }
 
-    private CourseBuilder newCourse(){
+    private CourseBuilder newCourse() {
         return Course.builder()
                 .id(id)
                 .title(title)
diff --git a/src/main/java/com/github/cleanddd/model/Student.java b/src/main/java/com/github/cleanddd/model/Student.java
index 67062c2..c152437 100644
--- a/src/main/java/com/github/cleanddd/model/Student.java
+++ b/src/main/java/com/github/cleanddd/model/Student.java
@@ -42,7 +42,7 @@ public class Student {
                 .build();
     }
 
-    private StudentBuilder newStudent(){
+    private StudentBuilder newStudent() {
         return Student.builder()
                 .id(id)
                 .fullName(fullName)
diff --git a/src/main/java/com/github/cleanddd/presenter/RestPresenter.java b/src/main/java/com/github/cleanddd/presenter/RestPresenter.java
index 54d98e3..f47212b 100644
--- a/src/main/java/com/github/cleanddd/presenter/RestPresenter.java
+++ b/src/main/java/com/github/cleanddd/presenter/RestPresenter.java
@@ -54,10 +54,9 @@ public class RestPresenter implements RestPresenterOutputPort {
         final DelegatingServerHttpResponse httpOutputMessage =
                 new DelegatingServerHttpResponse(new ServletServerHttpResponse(httpServletResponse));
 
-        if (t instanceof EntityDoesNotExistError){
+        if (t instanceof EntityDoesNotExistError) {
             httpOutputMessage.setStatusCode(HttpStatus.BAD_REQUEST);
-        }
-        else {
+        } else {
             httpOutputMessage.setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);
         }
 
diff --git a/src/main/java/com/github/cleanddd/usecase/EnrollStudentUseCase.java b/src/main/java/com/github/cleanddd/usecase/EnrollStudentUseCase.java
index 9e7889e..8bda915 100644
--- a/src/main/java/com/github/cleanddd/usecase/EnrollStudentUseCase.java
+++ b/src/main/java/com/github/cleanddd/usecase/EnrollStudentUseCase.java
@@ -10,7 +10,6 @@ import com.github.cleanddd.port.PersistenceOperationsOutputPort;
 import com.github.cleanddd.port.RestPresenterOutputPort;
 
 import javax.transaction.Transactional;
-import java.util.Map;
 
 public class EnrollStudentUseCase implements EnrollStudentInputPort {