addTickMarks method
      
void
addTickMarks()
      
     
    
    
Implementation
void addTickMarks() {
  tickMarks = [for (var x in getTickNumbers()) getTick(x, size: tickSize)];
  bigTickMarks = [
    for (var x in numbersWithElongatedTicks)
      getTick(x, size: tickSize * longTickMultiple)
  ];
  add([...tickMarks!, ...bigTickMarks!]);
}