data.json includes group attribute

Output/data.json

-{"nodes":[{"name":"StudieA","author":"MenschA","year":"JahrA","doi":"doiA","input":"true"},
-    {"name":"StudieB","author":"MenschB","year":"JahrB","doi":"doiB","input":"false"},
-    {"name":"StudieC","author":"MenschC","year":"JahrC","doi":"doiC","input":"true"},
-    {"name":"StudieD","author":"MenschD","year":"JahrD","doi":"doiD","input":"false"},
-    {"name":"StudieE","author":"MenschE","year":"JahrE","doi":"doiE","input":"false"},
-    {"name":"StudieF","author":"MenschF","year":"JahrF","doi":"doiF","input":"false"},
-    {"name":"StudieG","author":"MenschG","year":"JahrG","doi":"doiG","input":"false"},
-    {"name":"StudieH","author":"MenschH","year":"JahrH","doi":"doiH","input":"false"},
-    {"name":"StudieI","author":"MenschI","year":"JahrI","doi":"doiI","input":"false"}],
+{"nodes":[{"name":"StudieA","author":"MenschA","year":"JahrA","doi":"doiA","group":"input"},
+    {"name":"StudieB","author":"MenschB","year":"JahrB","doi":"doiB","group":"cited"},
+    {"name":"StudieC","author":"MenschC","year":"JahrC","doi":"doiC","group":"input"},
+    {"name":"StudieD","author":"MenschD","year":"JahrD","doi":"doiD","group":"cited"},
+    {"name":"StudieE","author":"MenschE","year":"JahrE","doi":"doiE","group":"cited"},
+    {"name":"StudieF","author":"MenschF","year":"JahrF","doi":"doiF","group":"cited"},
+    {"name":"StudieG","author":"MenschG","year":"JahrG","doi":"doiG","group":"citing"},
+    {"name":"StudieH","author":"MenschH","year":"JahrH","doi":"doiH","group":"cited"}, 
+    {"name":"StudieI","author":"MenschI","year":"JahrI","doi":"doiI","group":"citing"}],
 "links":[{"source":"doiA","target":"doiB"},
     {"source":"doiA","target":"doiC"},
     {"source":"doiC","target":"doiE"},
     {"source":"doiD","target":"doiB"},
+    {"source":"doiC","target":"doiB"},
     {"source":"doiA","target":"doiH"},
     {"source":"doiA","target":"doiI"},
     {"source":"doiI","target":"doiC"},
@@ -19,4 +20,4 @@
     {"source":"doiH","target":"doiI"},
     {"source":"doiE","target":"doiF"}
 
-    ]}
\ No newline at end of file
+    ]}