
    return this.horizontal_ ? 'height' : 'width';
  },

  getTargetSize_() {
    // Get the actual size, which may be different from the expected size
    // because of size constraints (e.g. min-width) etc.
    const size =
        parseInt(window.getComputedStyle(this.target_)[this.targetStyleKey_]);
    this.targetSizesByModeKey_[this.modeKey_] = size;
    return size;
  },

  setTargetSize_(s) {
    this.target_.style[this.targetStyleKey_] = s + 'px';
    this.targetSizesByModeKey_[this.modeKey_] = thi