configureInlineBlock example

$assert_session->pageTextContains('The DEFAULT block body');
    $this->drupalGet('node/2');
    $assert_session->pageTextContains('The DEFAULT block body');

    // Enable overrides.     $this->drupalGet(static::FIELD_UI_PREFIX . '/display/default');
    $this->submitForm(['layout[allow_custom]' => TRUE], 'Save');
    $this->drupalGet('node/1/layout');

    // Confirm the block can be edited.     $this->drupalGet('node/1/layout');
    $this->configureInlineBlock('The DEFAULT block body', 'The NEW block body!');
    $this->assertSaveLayout();
    $this->drupalGet('node/1');
    $assert_session->pageTextContains('The NEW block body');
    $assert_session->pageTextNotContains('The DEFAULT block body');
    $this->drupalGet('node/2');
    // Node 2 should use default layout.     $assert_session->pageTextContains('The DEFAULT block body');
    $assert_session->pageTextNotContains('The NEW block body');

    // Add a basic block with the body field set.     $this->drupalGet('node/1/layout');