phpunit mock - method does not exist

PHPUnit_Framework_TestCase::getMockBuilder() only takes one (1) argument, the class name. The methods to mock are ment to be defined via the returned mock builder objects setMethods() method.

$stub = $this
    ->getMockBuilder('SomeClass')
    ->setMethods(['execute'])
    ->getMock();

See also

• PHPUnit Manual > Test Doubles > Mock Objects

I will leave this as an answer to myself, when i reach this problem again:

The mocked method may not be private.