/**
  * Test to ensure that only the expected empty array is returned from null
  * and incorrect data from the CalculateMethod class
  *
  * @return null
  */
 public function testRoyalmailClassNull()
 {
     $this->assertEquals($this->_emptyArray, $this->_carrier->getRates(null, 123123123123, 0.1));
     $this->assertEquals($this->_emptyArray, $this->_carrier->getRates(null, null, 0.1));
     $this->assertEquals($this->_emptyArray, $this->_carrier->getRates('GB', null, 0.1));
     $this->assertEquals($this->_emptyArray, $this->_carrier->getRates('GB', null, null));
     $this->assertEquals($this->_emptyArray, $this->_carrier->getRates('GB', 123123123123, null));
     $this->assertEquals($this->_emptyArray, $this->_carrier->getRates(null, null, null));
 }