1. @DomName('SVGGraphicsElement.hasExtension')
  2. @DocsEditable()
  3. @Experimental()
bool hasExtension(String extension)

Source 

@DomName('SVGGraphicsElement.hasExtension')
@DocsEditable()
@Experimental() // untriaged
bool hasExtension(String extension) => _blink.BlinkSVGGraphicsElement.instance
    .hasExtension_Callback_1_(this, extension);