title: munit throw a specific exception
body: <p>I am trying to throw a Filter Unaccepted Exception in munit to test my error handling but I am getting this error</p>
  
  <pre><code>org.mule.api.MessagingException: Failed to invoke throw-an.
  at get_data_filter_unaccepted_exception-test.mock:throw-an{doc:name=Throw unaccepted Exception, exception-ref=#[new org.mule.api.routing.filter.FilterUnacceptedException()], whenCalling=.*:.*}(get_data_from_qcfc-test-suite.xml:316)
  at appleFlow.munit:test{initialState=started, description=Test, ignore=false, abstract=false, id=MunitTestFlow$$EnhancerByMUNIT$$904837f0{get_data_filter_unaccepted_exception-test}}(get_data_from_qcfc-test-suite.xml:315)
  Caused by: org.mule.api.expression.ExpressionRuntimeException: Execution of the expression "new org.mule.api.routing.filter.FilterUnacceptedException()" failed.
      at org.mule.el.mvel.MVELExpressionLanguage.evaluateInternal(MVELExpressionLanguage.java:232)
  </code></pre>
  
  <p>This is my throw an exception</p>
  
  <pre><code>&lt;mock:when messageProcessor=".*:.*" doc:name="Mock API Token Web Service Call"&gt;
          &lt;mock:with-attributes&gt;
              &lt;mock:with-attribute name="doc:name" whereValue="#['Get API Token']"/&gt;
          &lt;/mock:with-attributes&gt;
          &lt;mock:then-return payload="#[getResource('api_token_success.xml').asString()]" mimeType="application/xml"/&gt;
  
      &lt;/mock:when&gt;
  </code></pre>
  
  <p>I think it is because of my MEL statement  </p>
  
  <pre><code>#[new org.mule.api.routing.filter.FilterUnacceptedException()]
  </code></pre>