in Source/Charts/Renderers/DataRenderer.swift [45:59]
func isDrawingValuesAllowed(dataProvider: ChartDataProvider?) -> Bool
/// Creates an ```NSUIAccessibilityElement``` that acts as the first and primary header describing a chart view.
///
/// - Parameters:
/// - chart: The chartView object being described
/// - data: A non optional data source about the chart
/// - defaultDescription: A simple string describing the type/design of Chart.
/// - Returns: A header ```NSUIAccessibilityElement``` that can be added to accessibleChartElements.
func createAccessibleHeader(usingChart chart: ChartViewBase,
andData data: ChartData,
withDefaultDescription defaultDescription: String) -> NSUIAccessibilityElement
}
internal struct AccessibleHeader {