public function testGraphIsNotWritableAfterInitializing() { $op1 = new GenericOperation(1); $op2 = new GenericOperation(2); $op3 = new GenericOperation(3); $op4 = new GenericOperation(4); $dm = new DependencyManager(); $dm->addOperation($op1); $dm->addOperation($op2); $dm->addOperation($op3); $dm->addOperation($op4); $dm->addDependencyByOperation($op1, $op2); $dm->addDependencyByOperation($op1, $op3); $dm->addDependencyByOperation($op2, $op4); $dm->addDependencyByOperation($op3, $op4); $dm->getExecutableOperations(); $this->setExpectedException('MikeRoetgers\\DependencyGraph\\Exception\\GraphWriteException'); $dm->addDependencyByOperation($op1, $op4); }