'#description'=>$this->t('Use a number character as a textual snippet for this search result. "0" equals "nosnippet". "-1" will let the search engine decide the most effective length.'),
];
$form['robots-keyed']['max-video-preview']=[
'#type'=>'number',
'#min'=>-1,
'#title'=>$this->t('Max Video Preview'),
'#description'=>$this->t('Use a maximum of number seconds as a video snippet for videos on this page in search results. "0" will use a static a image. "-1" means there is no limit.'),
];
$form['robots-keyed']['max-image-preview']=[
'#type'=>'select',
'#title'=>$this->t('Max Image Preview'),
'#description'=>$this->t('Set the maximum size of an image preview for this page in a search results.'),
'#options'=>[
'none'=>$this->t('None - no image preview is to be shown.'),
'standard'=>$this->t('Standard - a default image preview may be shown.'),
'large'=>$this->t('Large - a larger image preview, up to the width of the viewport, may be shown.'),
],
'#empty_option'=>$this->t('Select'),
];
$form['robots-keyed']['unavailable_after']=[
'#type'=>'date',
'#title'=>$this->t('Unavailable after date'),
'#description'=>$this->t('Do not show this page in search results after the specified date'),
];
// Prepare the default value as it is stored as a string.