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+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<diagram program="umlet" version="14.2">
+  <zoom_level>13</zoom_level>
+  <element>
+    <id>UMLActor</id>
+    <coordinates>
+      <x>0</x>
+      <y>208</y>
+      <w>104</w>
+      <h>156</h>
+    </coordinates>
+    <panel_attributes>Participant
+</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>65</x>
+      <y>221</y>
+      <w>442</w>
+      <h>104</h>
+    </coordinates>
+    <panel_attributes/>
+    <additional_attributes>10.0;10.0;320.0;60.0</additional_attributes>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>884</x>
+      <y>208</y>
+      <w>182</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes>join created
+room</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>676</x>
+      <y>481</y>
+      <w>156</w>
+      <h>65</h>
+    </coordinates>
+    <panel_attributes>create content
+for room</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>520</x>
+      <y>65</y>
+      <w>156</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes>give a
+comment</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>481</x>
+      <y>169</y>
+      <w>156</w>
+      <h>65</h>
+    </coordinates>
+    <panel_attributes>show content
+in room</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>377</x>
+      <y>715</y>
+      <w>156</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes>see feedback</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>975</x>
+      <y>611</y>
+      <w>208</w>
+      <h>65</h>
+    </coordinates>
+    <panel_attributes>see answer statistics</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>806</x>
+      <y>507</y>
+      <w>195</w>
+      <h>156</h>
+    </coordinates>
+    <panel_attributes>lt=.&gt;
+&lt;&lt;extends&gt;&gt;</panel_attributes>
+    <additional_attributes>130.0;100.0;10.0;17.0</additional_attributes>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>1001</x>
+      <y>468</y>
+      <w>169</w>
+      <h>78</h>
+    </coordinates>
+    <panel_attributes>start new 
+voting round</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>819</x>
+      <y>481</y>
+      <w>208</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes>lt=.&gt;
+&lt;&lt;extends&gt;&gt;</panel_attributes>
+    <additional_attributes>140.0;20.0;10.0;20.0</additional_attributes>
+  </element>
+  <element>
+    <id>UMLClass</id>
+    <coordinates>
+      <x>156</x>
+      <y>13</y>
+      <w>156</w>
+      <h>39</h>
+    </coordinates>
+    <panel_attributes>ARSnova</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLActor</id>
+    <coordinates>
+      <x>0</x>
+      <y>546</y>
+      <w>78</w>
+      <h>156</h>
+    </coordinates>
+    <panel_attributes>Creator
+</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLClass</id>
+    <coordinates>
+      <x>156</x>
+      <y>13</y>
+      <w>1144</w>
+      <h>949</h>
+    </coordinates>
+    <panel_attributes>
+</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>481</x>
+      <y>273</y>
+      <w>156</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes>give feedback
+</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>416</x>
+      <y>598</y>
+      <w>156</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes>create room
+</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>26</x>
+      <y>559</y>
+      <w>416</w>
+      <h>91</h>
+    </coordinates>
+    <panel_attributes/>
+    <additional_attributes>300.0;50.0;10.0;10.0</additional_attributes>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>663</x>
+      <y>637</y>
+      <w>156</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes>login</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>546</x>
+      <y>624</y>
+      <w>143</w>
+      <h>65</h>
+    </coordinates>
+    <panel_attributes>lt=&lt;.
+&lt;&lt;include&gt;&gt;</panel_attributes>
+    <additional_attributes>90.0;30.0;10.0;10.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>663</x>
+      <y>78</y>
+      <w>247</w>
+      <h>169</h>
+    </coordinates>
+    <panel_attributes>lt=&lt;.
+&lt;&lt;include&gt;&gt;</panel_attributes>
+    <additional_attributes>10.0;10.0;170.0;110.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>624</x>
+      <y>195</y>
+      <w>286</w>
+      <h>65</h>
+    </coordinates>
+    <panel_attributes>lt=&lt;.
+&lt;&lt;include&gt;&gt;</panel_attributes>
+    <additional_attributes>10.0;10.0;200.0;30.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>624</x>
+      <y>234</y>
+      <w>286</w>
+      <h>91</h>
+    </coordinates>
+    <panel_attributes>lt=&lt;.
+&lt;&lt;include&gt;&gt;</panel_attributes>
+    <additional_attributes>10.0;50.0;200.0;10.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>52</x>
+      <y>507</y>
+      <w>650</w>
+      <h>78</h>
+    </coordinates>
+    <panel_attributes/>
+    <additional_attributes>10.0;40.0;480.0;10.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>520</x>
+      <y>533</y>
+      <w>260</w>
+      <h>91</h>
+    </coordinates>
+    <panel_attributes>lt=&lt;.
+&lt;&lt;include&gt;&gt;</panel_attributes>
+    <additional_attributes>10.0;50.0;180.0;10.0</additional_attributes>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>429</x>
+      <y>832</y>
+      <w>156</w>
+      <h>78</h>
+    </coordinates>
+    <panel_attributes>see participant's
+comments</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>39</x>
+      <y>598</y>
+      <w>416</w>
+      <h>286</h>
+    </coordinates>
+    <panel_attributes/>
+    <additional_attributes>10.0;10.0;300.0;200.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>39</x>
+      <y>585</y>
+      <w>364</w>
+      <h>182</h>
+    </coordinates>
+    <panel_attributes/>
+    <additional_attributes>10.0;10.0;260.0;120.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>520</x>
+      <y>637</y>
+      <w>117</w>
+      <h>130</h>
+    </coordinates>
+    <panel_attributes>lt=&lt;.
+&lt;&lt;include&gt;&gt;</panel_attributes>
+    <additional_attributes>10.0;10.0;10.0;80.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>65</x>
+      <y>195</y>
+      <w>455</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes/>
+    <additional_attributes>10.0;20.0;330.0;20.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>65</x>
+      <y>78</y>
+      <w>481</w>
+      <h>156</h>
+    </coordinates>
+    <panel_attributes/>
+    <additional_attributes>10.0;100.0;350.0;10.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>533</x>
+      <y>624</y>
+      <w>130</w>
+      <h>273</h>
+    </coordinates>
+    <panel_attributes>lt=&lt;.
+&lt;&lt;include&gt;&gt;</panel_attributes>
+    <additional_attributes>10.0;10.0;40.0;190.0</additional_attributes>
+  </element>
+  <element>
+    <id>UMLUseCase</id>
+    <coordinates>
+      <x>338</x>
+      <y>26</y>
+      <w>182</w>
+      <h>52</h>
+    </coordinates>
+    <panel_attributes>give answer
+to a content</panel_attributes>
+    <additional_attributes/>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>403</x>
+      <y>65</y>
+      <w>156</w>
+      <h>156</h>
+    </coordinates>
+    <panel_attributes>lt=.&gt;
+&lt;&lt;extends&gt;&gt;</panel_attributes>
+    <additional_attributes>60.0;100.0;10.0;10.0</additional_attributes>
+  </element>
+  <element>
+    <id>Relation</id>
+    <coordinates>
+      <x>65</x>
+      <y>65</y>
+      <w>351</w>
+      <h>156</h>
+    </coordinates>
+    <panel_attributes/>
+    <additional_attributes>250.0;10.0;10.0;100.0</additional_attributes>
+  </element>
+</diagram>