The base class for all classes that provide values available to build a series' label text.
@property (readonly, nullable) NSArray *pointIndexes
Array of int values that specify indices of data points that are aggregated to the series point for which the chart should display a label.
Returns the name of a series containing a data point for which a label is formed.
@property (readonly, copy, nonatomic, nullable) NSString *seriesName
The series name.