### Question:
UniqueColumnCombination implements Result { public ColumnCombination getColumnCombination() { return columnCombination; } protected  UniqueColumnCombination();  UniqueColumnCombination(ColumnIdentifier... columnIdentifier);  UniqueColumnCombination(ColumnCombination columnCombination); ColumnCombination getColumnCombination(); void setColumnCombination(ColumnCombination columnCombination); @Override @XmlTransient void sendResultTo(OmniscientResultReceiver resultReceiver); @Override String toString(); String toString(Map<String, String> tableMapping, Map<String, String> columnMapping); static UniqueColumnCombination fromString(Map<String, String> tableMapping, Map<String, String> columnMapping, String str); @Override int hashCode(); @Override boolean equals(Object obj);  }### Answer:
@Test public void testConstructorColumnIdentifiers() { ColumnIdentifier expectedColumn1 = new ColumnIdentifier("table1", "column1"); ColumnIdentifier expectedColumn2 = new ColumnIdentifier("table2", "column2"); UniqueColumnCombination actualUniqueColumnCombination = new UniqueColumnCombination(expectedColumn1, expectedColumn2, expectedColumn2); assertEquals(new ColumnCombination(expectedColumn1, expectedColumn2), actualUniqueColumnCombination.getColumnCombination()); }
@Test public void testConstructorColumnCombination() { ColumnIdentifier expectedColumn1 = new ColumnIdentifier("table1", "column1"); ColumnIdentifier expectedColumn2 = new ColumnIdentifier("table2", "column2"); ColumnCombination expectedColumnCombination = new ColumnCombination(expectedColumn1, expectedColumn2, expectedColumn2); UniqueColumnCombination actualUniqueColumnCombination = new UniqueColumnCombination(expectedColumnCombination); assertEquals(expectedColumnCombination, actualUniqueColumnCombination.getColumnCombination()); }