mainPath
Returns the main horizon path. The main path is the path on which the likeliest map-matched on-road position is located. If there is no on-road map-matched position candidate, there is no main path either because no horizon can be provided. See HorizonPosition for more details.
Return
Main horizon path. Null if there is no main path because no horizon can be generated (there is no on-road map-matched position candidate). See HorizonPosition for more details.