nl_tokens: Get a style property value .
pl_tokens: function getPropertyValue ( cssRule : HTMLElementWithStyleMap | CSSStyleRule | CSSKeyframeRule , prop : string ) : string { try { // Support CSSTOM. if ( cssRule . attributeStyleMap ) { return cssRule . attributeStyleMap . get ( prop ) } return cssRule . <mask> . getPropertyValue ( prop ) } catch ( err ) { // IE may throw if property is unknown. return '' } }