### Question:
Relation extends Expression { @Override public int getRequiredComponentWidthCount() { return getColumn().size() + STATIC_COLUMNS; } Relation();  Relation(final Id id,
                    final Description description,
                    final QName typeRef,
                    final java.util.List<InformationItem> column,
                    final java.util.List<List> row); @Override Relation copy(); java.util.List<InformationItem> getColumn(); java.util.List<List> getRow(); @Override java.util.List<HasTypeRef> getHasTypeRefs(); @Override int getRequiredComponentWidthCount(); @Override boolean equals(final Object o); @Override int hashCode(); static final int STATIC_COLUMNS; }### Answer:
@Test public void testComponentWidths() { assertEquals(relation.getRequiredComponentWidthCount(), relation.getComponentWidths().size()); relation.getComponentWidths().forEach(Assert::assertNull); }