### Question:
UndefinedNode extends AbstractExprNode { @Override public boolean isLeaf() { return false; } private  UndefinedNode(); @Override boolean isLeaf(); @Override Object accept( FilterVisitor visitor ); @Override boolean isSchemaAware(); @Override String toString(); static final UndefinedNode UNDEFINED_NODE; }### Answer:
@Test public void testIsLeaf() throws Exception { assertFalse( undefinedNode.isLeaf() ); }