### Question:
Column implements Cloneable { public void convertToString() { if (value.isPresent()) { this.value = Optional.of(String.valueOf(value)); } } Column(int index, String name, Object value);  Column(int index, String name, String targetSink, Object value);  Column(int index, String name); void convertToInteger(); void convertToDouble(); void convertDMSToDouble(); void convertToBoolean(); void fillWithValue(String value); void convertToString(); boolean isNullValue(); String getName(); Object getValue(); Optional<Object> getValueAsOptional(); int getIndex(); void setIndex(int index); String getTargetSink(); String getTargetObject(); void setName(String name); void setTargetSink(String targetSink); void setTargetObject(String targetObject); void setValue(Object value); @Override int hashCode(); @Override boolean equals(Object obj); @Override Column clone(); @Override String toString();  }### Answer:
@Test public void convertToString() { Column column = new Column(0, "name", 42); assertTrue(column.getValue() instanceof Integer); column.convertToString(); assertTrue(column.getValue() instanceof String); }