Bug 239015 [Databinding] ObservableListTreeContentProvider adds the value passed to TreeViewer#setInput() to the known-elements
The input element is never shown in the viewer so it should no get part of the knownElements further more it restricts the usability of the content-provider because the input-element itself already has to provide the required Observable-Attribute(s).
tests/org.eclipse.jface.tests.databinding/src/org/eclipse/jface/tests/databinding/BindingTestSuite.java
import org.eclipse.core.tests.databinding.beans.BeansObservablesTest;
import org.eclipse.core.tests.databinding.beans.PojoObservablesTest;
import org.eclipse.core.tests.databinding.conversion.NumberToStringConverterTest;
import org.eclipse.core.tests.databinding.conversion.StringToNumberConverterTest;
import org.eclipse.core.tests.databinding.observable.AbstractObservableTest;
import org.eclipse.core.tests.databinding.observable.DiffsTest;
import org.eclipse.core.tests.databinding.observable.Diffs_ListDiffTests;
import org.eclipse.core.tests.databinding.observable.ObservableTrackerTest;
import org.eclipse.core.tests.databinding.observable.ObservablesTest;
import org.eclipse.core.tests.databinding.observable.RealmTest;
import org.eclipse.core.tests.databinding.observable.list.AbstractObservableListTest;
import org.eclipse.core.tests.databinding.observable.list.ComputedListTest;
import org.eclipse.core.tests.databinding.observable.list.ListDiffTest;
import org.eclipse.core.tests.databinding.observable.list.ListDiffVisitorTest;
import org.eclipse.core.tests.databinding.observable.list.ObservableListTest;
import org.eclipse.core.tests.databinding.observable.list.WritableListTest;
import org.eclipse.core.tests.databinding.observable.map.AbstractObservableMapTest;
import org.eclipse.core.tests.databinding.observable.map.CompositeMapTest;
import org.eclipse.core.tests.databinding.observable.map.ObservableMapTest;
import org.eclipse.core.tests.databinding.observable.map.WritableMapTest;
import org.eclipse.core.tests.databinding.observable.set.AbstractObservableSetTest;
import org.eclipse.core.tests.databinding.observable.set.ObservableSetTest;
import org.eclipse.core.tests.databinding.observable.set.UnionSetTest;
import org.eclipse.core.tests.databinding.observable.set.WritableSetTest;
import org.eclipse.core.tests.databinding.observable.value.AbstractObservableValueTest;
import org.eclipse.core.tests.databinding.observable.value.AbstractVetoableValueTest;
import org.eclipse.core.tests.databinding.observable.value.ComputedValueTest;
import org.eclipse.core.tests.databinding.observable.value.WritableValueTest;
import org.eclipse.core.tests.databinding.validation.MultiValidatorTest;
import org.eclipse.core.tests.databinding.validation.ValidationStatusTest;