getLineDash method Null safety

1. Dart
2. dart:html
3. PaintRenderingContext2D
4. getLineDash method

PaintRenderingContext2D class

1. Properties
2. currentTransform
3. fillStyle
4. filter
5. globalAlpha
6. globalCompositeOperation
7. hashCode
8. imageSmoothingEnabled
9. imageSmoothingQuality
10. lineCap
11. lineDashOffset
12. lineJoin
13. lineWidth
14. miterLimit
15. runtimeType
16. shadowBlur
17. shadowColor
18. shadowOffsetX
19. shadowOffsetY
20. strokeStyle
21. Methods
22. arc
23. arcTo
24. beginPath
25. bezierCurveTo
26. clearRect
27. clip
28. closePath
29. createLinearGradient
30. createPattern
31. createRadialGradient
32. drawImage
33. ellipse
34. fill
35. fillRect
36. getLineDash
37. isPointInPath
38. isPointInStroke
39. lineTo
40. moveTo
41. noSuchMethod
42. quadraticCurveTo
43. rect
44. resetTransform
45. restore
46. rotate
47. save
48. scale
49. setLineDash
50. setTransform
51. stroke
52. strokeRect
53. toString
54. transform
55. translate
56. Operators
57. operator ==