Resolved confilics with master

Signed-off-by: Marcin Woźniak <y0rune@aol.com>

buisnesslogic/src/main/java/com/plannaplan/services/GroupService.java

@@ -1,7 +1,11 @@
 package com.plannaplan.services;
 
+import java.util.HashMap;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.function.Function;
 
 import com.plannaplan.entities.Groups;
 import com.plannaplan.repositories.GroupRepository;
@@ -30,8 +34,7 @@ public class GroupService {
     }
 
     public Groups save(Groups group) {
-        this.repo.save(group);
-        return group;
+        return this.repo.save(group);
     }
 
     public void delete(Groups groups) {
@@ -55,4 +58,30 @@ public class GroupService {
         return Optional.empty();
 
     }
+
+    /**
+     * 
+     * @param groups list of groups you want to get taken places ammount
+     * @return HashMap<Long, Integer> where Long is group id and Integer is how many
+     *         places in gorup is already taken
+     */
+    public HashMap<Long, Integer> getTakenPlaces(List<Groups> groups) {
+        HashMap<Long, Integer> response = new HashMap<>();
+
+        List<Object[]> respoonses = this.repo
+                .getAssignedAmounts(groups.stream().filter(Objects::nonNull).map(new Function<Groups, Long>() {
+                    @Override
+                    public Long apply(Groups p) {
+                        final Long id = p.getId();
+                        response.put(id, 0);
+                        return id;
+                    }
+                }).collect(Collectors.toList()));
+
+        for (Object[] element : respoonses) {
+            response.put(((Groups) element[0]).getId(), ((Long) element[1]).intValue());
+        }
+
+        return response;
+    }
 }