Map camera anchor value. Default value is NULL meaning center of given map view. Left-top corner is represented as ScreenCoordinate (0.0, 0.0).
If anchor is set to some specific value (set directly or by some running anchor animation) it will be used as anchor for all upcoming animations even if they do not animate anchor directly.
Note: If anchor animator is started and no start value is specified explicitly and anchor = NULL - then start value will be set to ScreenCoordinate(0.0, 0.0) automatically and it will be start point for interpolation.