OpacityAnimator shouldn't require explicit from value

import QtQuick 2.6

Rectangle {
    width: 300
    height: 300
    Rectangle {
        id: item
        color: "black"
        width: 100
        height: 100
        anchors.centerIn: parent
        NumberAnimation {
            target: item
            duration: 2000
            property: "opacity"
            to: 0.0 // Animates from implicit 1.0
            running: false
        }
        OpacityAnimator {
            target: item
            duration: 2000
            to: 0.0 // Doesn't animate from the initial opacity 1.0
            running: true
        }
   }
}