Fill missing values in the data frame with the nearest available value (using the specified direction). Note that the frame may still contain missing values after call to this function (e.g. if the first value is not available and we attempt to fill series with previous values). This operation can only be used on ordered frames. ## Parameters - `frame` - An input data frame that is to be filled - `direction` - Specifies the direction used when searching for the nearest available value. `Backward` means that we want to look for the first value with a smaller key while `Forward` searches for the nearest greater key. [category:Missing values]

public static Frame<R, C> FillMissing<R, C>(
	Direction direction,
	Frame<R, C> frame
)