code: function fitsVerticallyWithCenteredAnchor(anchorBorderBox, flyoutMeasurements) {
                              // Returns true if the flyout would always fit at least top
                              // or bottom of its anchor, regardless of the position of the anchor,
                              // as long as the anchor never changed its height, nor did the height of
                              // the visualViewport change.
                              return ((_Overlay._Overlay._keyboardInfo._visibleDocHeight - anchorBorderBox.height) / 2) >= flyoutMeasurements.totalHeight;
                          }
docs: If the anchor is centered vertically, would the flyout fit above it?