measures for multiple sentence counts, improved test suite
diff --git a/t/artificial/opennlp/morpho.xml b/t/artificial/opennlp/morpho.xml
new file mode 100644
index 0000000..1145c4e
--- /dev/null
+++ b/t/artificial/opennlp/morpho.xml
@@ -0,0 +1,184 @@
+<?xml version="1.0" encoding="UTF-8"?><?xml-model href="span.rng" type="application/xml" schematypens="http://relaxng.org/ns/structure/1.0"?><layer xmlns="http://ids-mannheim.de/ns/KorAP" docid="A01_APR.13047" VERSION="KorAP-0.4">
+   <spanList>
+      <span id="s_7" from="0" to="3">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">APPRART</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_8" from="4" to="11">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">ADJA</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_9" from="12" to="23">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">ADJA</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_10" from="24" to="30">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">NN</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_11" from="31" to="35">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">VVFIN</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_12" from="36" to="39">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">ART</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_13" from="40" to="47">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">NN</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_14" from="48" to="51">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">ART</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_15" from="52" to="63">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">NN</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_16" from="64" to="73">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">NE</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_17" from="74" to="77">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">PTKVZ</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_18" from="77" to="78">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">$,</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_19" from="79" to="84">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">KOUS</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_20" from="85" to="88">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">ART</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_21" from="89" to="96">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">NN</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_22" from="97" to="101">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">NN</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_23" from="102" to="111">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">NN</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_24" from="112" to="123">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">VVPP</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_25" from="124" to="128">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">VAFIN</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+      <span id="s_26" from="128" to="129">
+         <fs xmlns="http://www.tei-c.org/ns/1.0" type="lex">
+            <f name="lex">
+               <fs>
+                  <f name="pos">$.</f>
+               </fs>
+            </f>
+         </fs>
+      </span>
+   </spanList>
+</layer>
diff --git a/t/artificial/opennlp/sentences.xml b/t/artificial/opennlp/sentences.xml
new file mode 100644
index 0000000..fcb2188
--- /dev/null
+++ b/t/artificial/opennlp/sentences.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?><?xml-model href="span.rng" type="application/xml" schematypens="http://relaxng.org/ns/structure/1.0"?><layer xmlns="http://ids-mannheim.de/ns/KorAP" docid="A01_APR.13047" VERSION="KorAP-0.4">
+   <spanList>
+      <span from="0" to="129"/>
+   </spanList>
+</layer>
diff --git a/t/artificial/opennlp/tokens.xml b/t/artificial/opennlp/tokens.xml
new file mode 100644
index 0000000..d0bc237
--- /dev/null
+++ b/t/artificial/opennlp/tokens.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?><?xml-model href="span.rng" type="application/xml" schematypens="http://relaxng.org/ns/structure/1.0"?><layer xmlns="http://ids-mannheim.de/ns/KorAP" docid="ART_00001" VERSION="KorAP-0.4">
+<spanList>
+  -43
+      <span id="s_7" from="0" to="3"/>
+      <span id="s_8" from="4" to="11"/>
+      <span id="s_9" from="12" to="23"/>
+      <span id="s_10" from="24" to="30"/>
+      <span id="s_11" from="31" to="35"/>
+      <span id="s_12" from="36" to="39"/>
+      <span id="s_13" from="40" to="47"/>
+      <span id="s_14" from="48" to="51"/>
+      <span id="s_15" from="52" to="63"/>
+      <span id="s_16" from="64" to="73"/>
+      <span id="s_17" from="74" to="77"/>
+      <span id="s_18" from="77" to="78"/>
+      <span id="s_19" from="79" to="84"/>
+      <span id="s_20" from="85" to="88"/>
+      <span id="s_21" from="89" to="96"/>
+      <span id="s_22" from="97" to="101"/>
+      <span id="s_23" from="102" to="111"/>
+      <span id="s_24" from="112" to="123"/>
+      <span id="s_25" from="124" to="128"/>
+      <span id="s_26" from="128" to="129"/>
+   </spanList>
+</layer>