public function testComputeFixedPoint()
 {
     $graph = new ControlFlowGraph($entry = $this->getAstNode());
     $node1 = $this->getAstNode();
     $graph->connect($entry, null, $node1);
     $node2 = $this->getAstNode();
     $graph->connect($node1, null, $node2);
     $node3 = $this->getAstNode();
     $graph->connect($node3, null, $node2);
     $node4 = $this->getAstNode();
     $graph->connect($node2, null, $node4);
     $callback = $this->getMock('Scrutinizer\\PhpAnalyzer\\ControlFlow\\EdgeCallbackInterface');
     $t = new FixedPointGraphTraversal($callback);
     $callback->expects($this->at(0))->method('traverseEdge')->with($entry, null, $node1)->will($this->returnValue(true));
     $callback->expects($this->at(1))->method('traverseEdge')->with($node1, null, $node2)->will($this->returnValue(false));
     $t->computeFixedPointWithEntry($graph, $entry);
 }