Test accordion plugin configuration form.
public function testConfigurationForm() {
$this
->drupalGet('admin/structure/paragraphs_type/accordion_content');
$this
->assertSession()
->pageTextContains('There are no fields available with the cardinality greater than one. Please add at least one in the Manage fields page.');
$this
->drupalGet('admin/structure/paragraphs_type/accordion');
$this
->assertSession()
->responseContains('Accordion effect for paragraphs.');
$this
->assertSession()
->optionExists('edit-behavior-plugins-accordion-settings-paragraph-accordion-field', 'paragraphs_accordion_paragraphs');
$this
->assertSession()
->responseContains('Choose a field to be used as the accordion container.');
}