### Question:
GraphNode extends AbstractBaseGraphObject implements IMutableGraphNode { public boolean hasRelations () { return m_aRelations != null && m_aRelations.isNotEmpty (); } GraphNode();  GraphNode(@Nullable final String sID); final boolean isDirected(); @Nonnull EChange addRelation(@Nullable final IMutableGraphRelation aRelation); @Nonnull EChange removeRelation(@Nullable final IMutableGraphRelation aRelation); @Nonnull EChange removeAllRelations(); boolean isConnectedWith(@Nullable final IMutableGraphNode aNode); @Nullable IMutableGraphRelation getRelation(@Nullable final IMutableGraphNode aNode); boolean hasRelations(); @Nonnegative int getRelationCount(); @Nonnull @ReturnsMutableCopy ICommonsOrderedSet <IMutableGraphRelation> getAllRelations(); @Nonnull @ReturnsMutableCopy ICommonsOrderedSet <String> getAllRelationIDs(); void forEachRelation(@Nonnull final Consumer <? super IMutableGraphRelation> aConsumer); @Nonnull @ReturnsMutableCopy ICommonsOrderedSet <IMutableGraphNode> getAllRelatedNodes(); @Nonnull @ReturnsMutableCopy ICommonsOrderedSet <String> getAllRelatedNodeIDs(); @Override boolean equals(final Object o); @Override int hashCode(); @Override String toString();  }### Answer:
@Test public void testCtor () { final GraphNode n = new GraphNode (); assertNotNull (n.getID ()); assertTrue (StringHelper.hasText (n.getID ())); final GraphNode n1 = new GraphNode (""); assertNotNull (n1.getID ()); assertTrue (StringHelper.hasText (n1.getID ())); assertFalse (n1.hasRelations ()); final GraphNode n3 = new GraphNode ("id1"); assertNotNull (n3.getID ()); assertEquals ("id1", n3.getID ()); }