protected function setUp()
 {
     $this->_model = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create('Magento\\Catalog\\Model\\Product\\Attribute\\Backend\\Tierprice');
     $this->productRepository = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create('Magento\\Catalog\\Model\\ProductRepository');
     $this->metadataPool = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create('Magento\\Framework\\Model\\Entity\\MetadataPool');
     $this->_model->setAttribute(\Magento\TestFramework\Helper\Bootstrap::getObjectManager()->get('Magento\\Eav\\Model\\Config')->getAttribute('catalog_product', 'tier_price'));
 }
 /**
  * {@inheritdoc}
  */
 public function setAttribute($attribute)
 {
     $pluginInfo = $this->pluginList->getNext($this->subjectType, 'setAttribute');
     if (!$pluginInfo) {
         return parent::setAttribute($attribute);
     } else {
         return $this->___callPlugins('setAttribute', func_get_args(), $pluginInfo);
     }
 }