diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
deleted file mode 100644
index 6318267..0000000
--- a/.github/workflows/maven.yml
+++ /dev/null
@@ -1,24 +0,0 @@
-# This workflow will build a Java project with Maven
-# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
-
-name: Java CI with Maven
-
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
-
-jobs:
-  build:
-
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v2
-    - name: Set up JDK 1.8
-      uses: actions/setup-java@v1
-      with:
-        java-version: 1.8
-    - name: Build with Maven
-      run: mvn clean install #-DskipTests
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index b058727..db7ab92 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -1,9 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ChangeListManager">
-    <list default="true" id="75ef5724-93bc-4ed4-82b2-ff12411188dc" name="Default Changelist" comment="">
-      <change beforePath="$PROJECT_DIR$/richedit/src/test/java/edu/lu/uni/serval/TestPredefinedCases.java" beforeDir="false" afterPath="$PROJECT_DIR$/richedit/src/test/java/edu/lu/uni/serval/TestPredefinedCases.java" afterDir="false" />
-    </list>
+    <list default="true" id="75ef5724-93bc-4ed4-82b2-ff12411188dc" name="Default Changelist" comment="" />
     <ignored path="$PROJECT_DIR$/classes/" />
     <ignored path="$PROJECT_DIR$/target/" />
     <ignored path="$PROJECT_DIR$/richedit/target/" />
@@ -24,11 +22,11 @@
   </component>
   <component name="FileEditorManager">
     <leaf SIDE_TABS_SIZE_LIMIT_KEY="300">
-      <file pinned="false" current-in-tab="true">
+      <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/richedit/src/test/java/edu/lu/uni/serval/TestPredefinedCases.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="193">
-              <caret line="24" column="28" selection-start-line="24" selection-start-column="28" selection-end-line="24" selection-end-column="28" />
+            <state relative-caret-position="178">
+              <caret line="23" column="28" selection-start-line="23" selection-start-column="28" selection-end-line="23" selection-end-column="28" />
             </state>
           </provider>
         </entry>
@@ -36,7 +34,7 @@
       <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/gumtree/core/src/test/java/com/github/gumtreediff/test/TestGumtreeMatcher.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="132">
+            <state relative-caret-position="40">
               <caret line="32" column="13" selection-start-line="32" selection-start-column="13" selection-end-line="32" selection-end-column="13" />
               <folding>
                 <element signature="imports" expanded="true" />
@@ -45,6 +43,15 @@
           </provider>
         </entry>
       </file>
+      <file pinned="false" current-in-tab="true">
+        <entry file="file://$PROJECT_DIR$/gumtree/core/src/test/java/com/github/gumtreediff/test/TestActionIo.java">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="90">
+              <caret line="36" column="13" selection-start-line="36" selection-start-column="13" selection-end-line="36" selection-end-column="13" />
+            </state>
+          </provider>
+        </entry>
+      </file>
       <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/richedit/src/main/java/edu/lu/uni/serval/richedit/ediff/EDiffHunkParser.java">
           <provider selected="true" editor-type-id="text-editor">
@@ -59,19 +66,6 @@
           <provider selected="true" editor-type-id="text-editor" />
         </entry>
       </file>
-      <file pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/gumtree/gen.srcml/src/main/java/com/github/gumtreediff/gen/srcml/AbstractSrcmlTreeGenerator.java">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="169">
-              <caret line="164" selection-start-line="164" selection-end-line="164" />
-              <folding>
-                <element signature="e#16976#16977#0" expanded="true" />
-                <element signature="e#17044#17045#0" expanded="true" />
-              </folding>
-            </state>
-          </provider>
-        </entry>
-      </file>
       <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/richedit/src/main/java/edu/lu/uni/serval/richedit/ediff/EDiffParser.java">
           <provider selected="true" editor-type-id="text-editor">
@@ -214,6 +208,7 @@
         <option value="$PROJECT_DIR$/gumtree/gen.srcml/src/main/java/com/github/gumtreediff/gen/srcml/NodeMap_new.java" />
         <option value="$PROJECT_DIR$/gumtree/gen.srcml/src/main/java/com/github/gumtreediff/gen/srcml/AbstractSrcmlTreeGenerator.java" />
         <option value="$PROJECT_DIR$/richedit/src/test/java/edu/lu/uni/serval/TestPredefinedCases.java" />
+        <option value="$PROJECT_DIR$/gumtree/core/src/test/java/com/github/gumtreediff/test/TestActionIo.java" />
       </list>
     </option>
   </component>
@@ -261,110 +256,6 @@
               <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
               <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
             </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="gumtree" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="gumtree" type="462c0819:PsiDirectoryNode" />
-              <item name="gen.srcml" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="gumtree" type="462c0819:PsiDirectoryNode" />
-              <item name="gen.srcml" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="gumtree" type="462c0819:PsiDirectoryNode" />
-              <item name="gen.srcml" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="gumtree" type="462c0819:PsiDirectoryNode" />
-              <item name="gen.srcml" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="462c0819:PsiDirectoryNode" />
-              <item name="java" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="gumtree" type="462c0819:PsiDirectoryNode" />
-              <item name="gen.srcml" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="462c0819:PsiDirectoryNode" />
-              <item name="java" type="462c0819:PsiDirectoryNode" />
-              <item name="srcml" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="richedit" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="richedit" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="richedit" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="richedit" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="462c0819:PsiDirectoryNode" />
-              <item name="resource" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="richedit" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="462c0819:PsiDirectoryNode" />
-              <item name="resource" type="462c0819:PsiDirectoryNode" />
-              <item name="testFiles" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="richedit" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="test" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="richedit" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="test" type="462c0819:PsiDirectoryNode" />
-              <item name="java" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
-              <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
-              <item name="richedit" type="462c0819:PsiDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="test" type="462c0819:PsiDirectoryNode" />
-              <item name="java" type="462c0819:PsiDirectoryNode" />
-              <item name="serval" type="462c0819:PsiDirectoryNode" />
-            </path>
             <path>
               <item name="gumtree" type="b2602c69:ProjectViewProjectNode" />
               <item name="fixminer_source" type="462c0819:PsiDirectoryNode" />
@@ -651,9 +542,8 @@
   </component>
   <component name="ToolWindowManager">
     <frame x="0" y="0" width="1680" height="1050" extended-state="0" />
-    <editor active="true" />
     <layout>
-      <window_info content_ui="combo" id="Project" order="0" sideWeight="0.49315068" visible="true" weight="0.30708182" />
+      <window_info active="true" content_ui="combo" id="Project" order="0" sideWeight="0.49315068" visible="true" weight="0.30708182" />
       <window_info id="Structure" order="1" sideWeight="0.5068493" side_tool="true" visible="true" weight="0.30708182" />
       <window_info id="Image Layers" order="2" />
       <window_info id="Designer" order="3" />
@@ -667,7 +557,7 @@
       <window_info anchor="bottom" id="Cvs" order="4" weight="0.25" />
       <window_info anchor="bottom" id="Inspection" order="5" weight="0.4" />
       <window_info anchor="bottom" id="TODO" order="6" />
-      <window_info active="true" anchor="bottom" id="Terminal" order="7" sideWeight="0.71428573" visible="true" weight="0.32959184" />
+      <window_info anchor="bottom" id="Terminal" order="7" sideWeight="0.71428573" visible="true" weight="0.32959184" />
       <window_info anchor="bottom" id="Event Log" order="8" sideWeight="0.50183153" side_tool="true" weight="0.4" />
       <window_info anchor="bottom" id="Version Control" order="9" />
       <window_info anchor="bottom" id="Messages" order="10" sideWeight="0.498779" weight="0.32959184" />
@@ -864,16 +754,6 @@
     </expressions>
   </component>
   <component name="editorHistoryManager">
-    <entry file="file://$PROJECT_DIR$/richedit/src/main/java/edu/lu/uni/serval/Launcher.java">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="396">
-          <caret line="81" column="80" selection-start-line="81" selection-start-column="71" selection-end-line="81" selection-end-column="80" />
-          <folding>
-            <element signature="imports" expanded="true" />
-          </folding>
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/python/data/datasets.csv">
       <provider selected="true" editor-type-id="text-editor" />
     </entry>
@@ -1239,9 +1119,16 @@
         </state>
       </provider>
     </entry>
+    <entry file="file://$PROJECT_DIR$/richedit/src/test/java/edu/lu/uni/serval/TestPredefinedCases.java">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="178">
+          <caret line="23" column="28" selection-start-line="23" selection-start-column="28" selection-end-line="23" selection-end-column="28" />
+        </state>
+      </provider>
+    </entry>
     <entry file="file://$PROJECT_DIR$/gumtree/core/src/test/java/com/github/gumtreediff/test/TestGumtreeMatcher.java">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="132">
+        <state relative-caret-position="40">
           <caret line="32" column="13" selection-start-line="32" selection-start-column="13" selection-end-line="32" selection-end-column="13" />
           <folding>
             <element signature="imports" expanded="true" />
@@ -1249,10 +1136,10 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/richedit/src/test/java/edu/lu/uni/serval/TestPredefinedCases.java">
+    <entry file="file://$PROJECT_DIR$/gumtree/core/src/test/java/com/github/gumtreediff/test/TestActionIo.java">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="193">
-          <caret line="24" column="28" selection-start-line="24" selection-start-column="28" selection-end-line="24" selection-end-column="28" />
+        <state relative-caret-position="90">
+          <caret line="36" column="13" selection-start-line="36" selection-start-column="13" selection-end-line="36" selection-end-column="13" />
         </state>
       </provider>
     </entry>