public function testAll()
 {
     $values = array('key1' => 'value1', 'key2' => 'value2');
     $imp = new Implementation($values);
     $this->assertEquals($values, $imp->all());
 }
 public function __construct($field, $operator, $values)
 {
     parent::__construct($field);
     $this->operator = $operator;
     $this->values = $values;
 }