int length

Source 

@DomName('SVGLengthList.length')
@DocsEditable()
@Experimental() // untriaged
int get length => _blink.BlinkSVGLengthList.instance.length_Getter_(this);
void length=(int value)

Source 

set length(int value) {
  throw new UnsupportedError("Cannot resize immutable List.");
}