thenUnset example

                            return $v;
                        })
                    ->end()
                    ->children()
                        ->scalarNode('child_node')->end()
                        ->booleanNode('bool_force_cast')->end()
                        ->integerNode('int_unset_at_zero')
                            ->validate()
                                ->ifTrue(fn ($value) => 0 === $value)
                                ->thenUnset()
                            ->end()
                        ->end()
                    ->end()
                ->end()
                ->arrayNode('simple_array_node')->end()
                ->enumNode('enum_node')->values(['a', 'b'])->end()
                ->variableNode('variable_node')->end()
                ->scalarNode('string_node')
                    ->validate()
                        ->ifTrue(fn ($value) => !\is_string($value) || 'fail' === $value)
                        ->thenInvalid('%s is not a valid string')
                    

$this->assertFalse($this->getField($node, 'normalizeKeys'));
    }

    public function testUnsetChild()
    {
        $node = new ArrayNodeDefinition('root');
        $node
            ->children()
                ->scalarNode('value')
                    ->beforeNormalization()
                        ->ifTrue(fn ($value) => empty($value))
                        ->thenUnset()
                    ->end()
                ->end()
            ->end()
        ;

        $this->assertSame([], $node->getNode()->normalize(['value' => null]));
    }

    public function testPrototypeVariable()
    {
        $node = new ArrayNodeDefinition('root');
        

$test = $this->getTestBuilder()
            ->ifString()
            ->thenInvalid('Invalid value')
        ->end();
        $this->finalizeTestBuilder($test);
    }

    public function testThenUnsetExpression()
    {
        $test = $this->getTestBuilder()
            ->ifString()
            ->thenUnset()
        ->end();
        $this->assertEquals([], $this->finalizeTestBuilder($test));
    }

    public function testEndIfPartNotSpecified()
    {
        $this->expectException(\RuntimeException::class);
        $this->expectExceptionMessage('You must specify an if part.');
        $this->getTestBuilder()->end();
    }