trait BlockCreationTrait

trait BlockCreationTrait {
    
    /**
     * Creates a block instance based on default settings.
     *
     * @param string $plugin_id
     *   The plugin ID of the block type for this block instance.
     * @param array $settings
     *   (optional) An associative array of settings for the block entity.
     *   Override the defaults by specifying the key and value in the array, for
     *   example:
     *   @code
     *     $this->drupalPlaceBlock('system_powered_by_block', array(
     *       'label' => t('Hello, world!'),
     *     ));
     *   @endcode
     *   The following defaults are provided:
     *   - label: Random string.
     *   - id: Random string.
     *   - region: 'sidebar_first'.
     *   - theme: The default theme.
     *   - visibility: Empty array.
     *
     * @return \Drupal\block\Entity\Block
     *   The block entity.
     *
     * @todo
     *   Add support for creating custom block instances.
     */
    protected function placeBlock($plugin_id, array $settings = []) {
        $config = \Drupal::configFactory();
        $settings += [
            'plugin' => $plugin_id,
            'region' => 'content',
            'id' => strtolower($this->randomMachineName(8)),
            'theme' => $config->get('system.theme')
                ->get('default'),
            'label' => $this->randomMachineName(8),
            'visibility' => [],
            'weight' => 0,
        ];
        $values = [];
        foreach ([
            'region',
            'id',
            'theme',
            'plugin',
            'weight',
            'visibility',
        ] as $key) {
            $values[$key] = $settings[$key];
            // Remove extra values that do not belong in the settings array.
            unset($settings[$key]);
        }
        foreach ($values['visibility'] as $id => $visibility) {
            $values['visibility'][$id]['id'] = $id;
        }
        $values['settings'] = $settings;
        $block = Block::create($values);
        $block->save();
        return $block;
    }

}