title: Issues with obfuscation in Java using ZKM
body: <p>Im trying to obfuscate an eclipse based java application. We are using ZKM script for Obfuscation.we recently added a new feature to the existing application where we have used the poi-3.9-20121203.jar third party jar and there are around 3 to 4 dependent jars for this. Im getting the below error when trying to obfuscate the code </p>
  
  <pre><code>Unexpected Error (D). Please report the problem to bugs@zelix.com
  
  com.zelix.m7: Class 'org.apache.poi.ss.usermodel.Sheet' in file 'D:\workSpace\Test   Ofucscation\Relea
  se3\mit\plugins\com.ins.hi.stores_1.0.0.201404081434.jar!lib/poi-3.9- 20121203.jar!org/a
  pache/poi/ss/usermodel/Sheet.class' has been opened and is implemented by class     'org.apache.poi.xssf
  .usermodel.XSSFSheet' in file 'D:\workSpace\TestOfucscation\Release3\mit\plugins\poi-ooxml-3.9-2
  0121203.jar!org/apache/poi/xssf/usermodel/XSSFSheet.class'. Class   'org.apache.poi.xssf.usermodel.XSS
  FSheet' is used by the opened classes but it has not been opened.  Either 'org.apache.poi.ss.usermod
  el.Sheet' should not be opened or 'org.apache.poi.xssf.usermodel.XSSFSheet' must also be opened for
   obfuscation. (B)
      at com.zelix.w1.a(w1.java:361)
      at com.zelix.w1.b(w1.java:95)
      at com.zelix.rp.a(rp.java:7)
      at com.zelix.rp.c(rp.java:113)
      at com.zelix.rp.a(rp.java:101)
      at com.zelix.q0.a(q0.java:128)
      at com.zelix.q0.a(q0.java:160)
      at com.zelix.zo.a(zo.java:463)
      at com.zelix.zo.a(zo.java:710)
      at com.zelix.zo.&lt;init&gt;(zo.java:351)
      at com.zelix.f3.a(f3.java:1130)
      at com.zelix.f3.a(f3.java:1249)
      at com.zelix.i2.a(i2.java:15)
      at com.zelix.q3.a(q3.java:222)
      at com.zelix.x1.a(x1.java:1490)
      at com.zelix.t1.a(t1.java:1793)
      at com.zelix.t1.a(t1.java:39)
      at com.zelix.oc.a(oc.java:96)
      at com.zelix.nc.a(nc.java:89)
      at com.zelix.mc.a(mc.java:22)
      at com.zelix.ic.a(ic.java:5)
      at com.zelix.ge.a(ge.java:3)
      at com.zelix.ak.a(ak.java:291)
      at com.zelix.ak.&lt;init&gt;(ak.java:438) 
  </code></pre>
  
  <p>Below are the things that I have done</p>
  
  <ol>
  <li>After including the new feature and third party jar in the application, I have updated the classpath of the third party jar&amp; all the dependent jars under the classpath in the Obfuscation_Script.txt.</li>
  <li>before executing the obfuscation script, i have replaced the poi-3.9.jar with only the classes that Im using in the classes that I have newly developed.  </li>
  </ol>
  
  <p>But im getting the above error when I run the obfuscation script. </p>
  
  <p>Any help on this is much appreciated. Thanks in Advance. </p>