Qt QML - margins at ChartView

Why does the ChartView object have margins other than the Rectangle object? How to make them the same? For example, if the ChartView object is replaced with a Rectangle, the margins become the same.

import QtQuick 2.7
import QtQuick.Controls 2.2
import QtCharts 2.2

Rectangle {
    anchors.fill: parent
    color: "#eeeeee"

    Rectangle {
        id: idRectConsole1
        width: 200
        anchors.top: parent.top
        anchors.left: parent.left
        anchors.bottom: parent.bottom
        anchors.margins: 20
        color: "#ffffff"

    }

    ChartView {
        anchors.top: parent.top
        anchors.left: idRectConsole1.right
        anchors.right: parent.right
        anchors.bottom: parent.bottom
        anchors.margins: 20
        legend.visible: false

        LineSeries {
            name: "1"
            XYPoint { x: 2; y: 0.73278}
            XYPoint { x: 4; y: 1.2213}
            XYPoint { x: 6; y: -0.73278}

        }
    }    
}