getFirstLeft method
Returns the first DataSet from the datasets-array that has it's dependency on the left axis. Returns null if no DataSet with left dependency could be found.
@return
Implementation
T? getFirstLeft(List<T> sets) {
for (T dataSet in sets) {
if (dataSet.getAxisDependency() == AxisDependency.left) return dataSet;
}
return null;
}