function mockElement(partial = {}) {
  return {
    src: 'https://www.paulirish.com/avatar150.jpg',
    srcset: '',
    displayedWidth: 200,
    displayedHeight: 200,
    clientRect: {
      top: 50,
      bottom: 250,
      left: 50,
      right: 250,
    },
    attributeWidth: '',
    attributeHeight: '',
    naturalDimensions: undefined,
    cssEffectiveRules: undefined,
    computedStyles: {position: 'absolute', objectFit: '', imageRendering: ''},
    isCss: false,
    isPicture: false,
    isInShadowDOM: false,
    node: {
      lhId: '__nodeid__',
      devtoolsNodePath: '1,HTML,1,BODY,1,DIV,1,IMG',
      selector: 'body > div > img',
      nodeLabel: 'img',
      snippet: '<img src="https://www.paulirish.com/avatar150.jpg">',
      boundingRect: {
        top: 50,
        bottom: 250,
        left: 50,
        right: 250,
        width: 200,
        height: 200,
      },
    },
    ...partial,
  };
}
@param {Partial<LH.Artifacts.ImageElement>=} partial
@return {LH.Artifacts.ImageElement}