diff --git a/tests/NestedSetsBehaviorTest.php b/tests/NestedSetsBehaviorTest.php
index 3d57610..b0f3489 100644
--- a/tests/NestedSetsBehaviorTest.php
+++ b/tests/NestedSetsBehaviorTest.php
@@ -356,7 +356,50 @@ class NestedSetsBehaviorTest extends DatabaseTestCase
      */
     public function testPrependExistsTo()
     {
-        $this->markTestSkipped();
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = Tree::findOne(9);
+        $node->prependTo(Tree::findOne(2));
+        $dataSet = $this->getConnection()->createDataSet(['tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree-after-prepend-exists-up-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = Tree::findOne(9);
+        $node->prependTo(Tree::findOne(16));
+        $dataSet = $this->getConnection()->createDataSet(['tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree-after-prepend-exists-down-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(31);
+        $node->prependTo(MultipleRootsTree::findOne(24));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-prepend-exists-up-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(31);
+        $node->prependTo(MultipleRootsTree::findOne(38));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-prepend-exists-down-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(9);
+        $node->prependTo(MultipleRootsTree::findOne(53));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-prepend-exists-another-tree-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
     }
 
     /**
@@ -408,7 +451,50 @@ class NestedSetsBehaviorTest extends DatabaseTestCase
      */
     public function testAppendExistsTo()
     {
-        $this->markTestSkipped();
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = Tree::findOne(9);
+        $node->appendTo(Tree::findOne(2));
+        $dataSet = $this->getConnection()->createDataSet(['tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree-after-append-exists-up-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = Tree::findOne(9);
+        $node->appendTo(Tree::findOne(16));
+        $dataSet = $this->getConnection()->createDataSet(['tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree-after-append-exists-down-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(31);
+        $node->appendTo(MultipleRootsTree::findOne(24));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-append-exists-up-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(31);
+        $node->appendTo(MultipleRootsTree::findOne(38));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-append-exists-down-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(9);
+        $node->appendTo(MultipleRootsTree::findOne(53));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-append-exists-another-tree-to.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
     }
 
     /**
@@ -460,7 +546,50 @@ class NestedSetsBehaviorTest extends DatabaseTestCase
      */
     public function testInsertExistsBefore()
     {
-        $this->markTestSkipped();
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = Tree::findOne(9);
+        $node->insertBefore(Tree::findOne(2));
+        $dataSet = $this->getConnection()->createDataSet(['tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree-after-insert-exists-before-up.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = Tree::findOne(9);
+        $node->insertBefore(Tree::findOne(16));
+        $dataSet = $this->getConnection()->createDataSet(['tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree-after-insert-exists-before-down.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(31);
+        $node->insertBefore(MultipleRootsTree::findOne(24));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-insert-exists-before-up.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(31);
+        $node->insertBefore(MultipleRootsTree::findOne(38));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-insert-exists-before-down.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(9);
+        $node->insertBefore(MultipleRootsTree::findOne(53));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-insert-exists-before-another-tree.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
     }
 
     /**
@@ -512,7 +641,50 @@ class NestedSetsBehaviorTest extends DatabaseTestCase
      */
     public function testInsertExistsAfter()
     {
-        $this->markTestSkipped();
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = Tree::findOne(9);
+        $node->insertAfter(Tree::findOne(2));
+        $dataSet = $this->getConnection()->createDataSet(['tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree-after-insert-exists-after-up.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = Tree::findOne(9);
+        $node->insertAfter(Tree::findOne(16));
+        $dataSet = $this->getConnection()->createDataSet(['tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/tree-after-insert-exists-after-down.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(31);
+        $node->insertAfter(MultipleRootsTree::findOne(24));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-insert-exists-after-up.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(31);
+        $node->insertAfter(MultipleRootsTree::findOne(38));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-insert-exists-after-down.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
+
+        $dataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree.xml');
+        $this->getDatabaseTester()->setDataSet($dataSet);
+        $this->getDatabaseTester()->onSetUp();
+        $node = MultipleRootsTree::findOne(9);
+        $node->insertAfter(MultipleRootsTree::findOne(53));
+        $dataSet = $this->getConnection()->createDataSet(['multiple_roots_tree']);
+        $expectedDataSet = $this->createFlatXMLDataSet(__DIR__ . '/datasets/multiple-roots-tree-after-insert-exists-after-another-tree.xml');
+        $this->assertDataSetsEqual($expectedDataSet, $dataSet);
     }
 
     /**