Unable to create Field extractor error caused by methods like public boolean setTime()

I used The clipse plugin to create a new drools project and added the example java class and rule file.

I have added the method below to the Message class:
public boolean setTime()

This result in the following error messages:
Unable to create Field Extractor for 'status' of '[ClassObjectType class=com.sample.DroolsTest$Message]' in rule 'Hello World' : [Rule name='Hello World']

Unable to create Field Extractor for 'message' : [Rule name='Hello World']
org.drools.RuntimeDroolsException: java.lang.ArrayIndexOutOfBoundsException: 0
Unable to create Field Extractor for 'status' of '[ClassObjectType class=com.sample.DroolsTest$Message]' in rule 'GoodBye' : [Rule name='GoodBye']

Unable to create Field Extractor for 'message' : [Rule name='GoodBye']
org.drools.RuntimeDroolsException: java.lang.ArrayIndexOutOfBoundsException: 0
Rule Compilation error : [Rule name='Hello World']
com/sample/Rule_Hello_World_0.java (7:416) : myMessage cannot be resolved

Rule Compilation error : [Rule name='GoodBye']
com/sample/Rule_GoodBye_0.java (7:343) : myMessage cannot be resolved

java.lang.IllegalArgumentException: Could not parse knowledge.
at com.sample.DroolsTest.readKnowledgeBase(DroolsTest.java:46)
at com.sample.DroolsTest.main(DroolsTest.java:23)

Adding a parameter to setTime or renameing it to something else then setXxxx, storeTime for example, does not result in an error.