/**
  * @covers \Elastica\Query\Builder::fieldOpen
  * @covers \Elastica\Query\Builder::fieldClose
  * @covers \Elastica\Query\Builder::open
  * @covers \Elastica\Query\Builder::close
  */
 public function testFieldOpenAndClose()
 {
     $this->assertSame($this->builder, $this->builder->fieldOpen('someField'));
     $this->assertSame($this->builder, $this->builder->fieldClose());
     $this->assertSame('{"someField":{}}', (string) $this->builder);
 }