PHPUnit：如何通过测试方法模拟内部调用的函数

In the below example, I want to mock the calling of getBaseValue() inside the multipliedValue(). But I cannot figure it out.

class Sample
{
    function multipliedValue()
    {
      $value = $this->getBaseValue();
      return $value * 2;
    }

    function getBaseValue()
    {
      return 2;
    }
}

I have used PHPUnit mocking, but it didn't work. So, I used the following code:

class SampleTest extends PHPUnit_Framework_TestCase
{
  function testMultipliedValueIfBaseValueIsFalse()
  {
        $mockedObject = $this->getMockBuilder(Sample::class)
            ->setMethods(['multipliedValue', 'getBaseValue'])
            ->getMock();
        $mockedObject->expects($this->any())
            ->method("getBaseValue")
            ->willReturn(false);
        $result = $mockedObject->multipliedValue();
        $this->assertFalse($result);
  }
}

I tried to create a global function, but only force one of the method to return my desired value, the rest just go as they are. How should I approach this test?

The error I am currently getting is for the $this in the multipliedValue() method, which treats it as the stubbed object.

All the methods listed in the ->setMethods() will be stubbed and return null by default so if you only want to stub getBaseValue then do:

$mockedObject = $this->getMockBuilder(Sample::class)
        ->setMethods(['getBaseValue'])
        ->getMock();
    $mockedObject->expects($this->any())
        ->method("getBaseValue")
        ->willReturn(false);
    $result = $mockedObject->multipliedValue();
    $this->assertFalse($result);