extracting methods, renaming, tests fix

Author: mtumilowicz

src/main/java/job/JobTitle.java

@@ -19,16 +19,20 @@ public enum JobTitle {
     private static ImmutableSet<JobTitle> OPERATIONAL =
             ImmutableSet.of(MANAGER, OFFICER);
 
-    public static Predicate<JobTitle> isAdministrative() {
-        return title -> ADMINISTRATION.contains(title);
+    public boolean isAdministration() {
+        return ADMINISTRATION.contains(this);
     }
 
-    public static Predicate<JobTitle> isOperational() {
-        return title -> OPERATIONAL.contains(title);
+    public boolean isOperational() {
+        return OPERATIONAL.contains(this);
     }
 
-    public static Predicate<JobTitle> isBusiness() {
-        return isAdministrative().or(isOperational());
+    public static Predicate<JobTitle> administration() {
+        return JobTitle::isAdministration;
+    }
+
+    public static Predicate<JobTitle> operational() {
+        return JobTitle::isOperational;
     }
 
     public static Stream<JobTitle> stream() {

src/test/java/job/JobTitleTest.java

@@ -2,7 +2,7 @@
 
 import org.junit.Test;
 
-import static job.JobTitle.isBusiness;
+import static job.JobTitle.*;
 
 /**
  * Created by mtumilowicz on 2018-11-07.
@@ -12,7 +12,7 @@ public class JobTitleTest {
     @Test
     public void isBusinessShowcase() {
         JobTitle.stream()
-                .filter(isBusiness())
+                .filter(administration().or(operational()))
                 .forEach(title -> System.out.println("Performed action for: " + title));
     }
 }