TreeGrid expand all crashes

[howudodat]

Describe the bug
Clicking the expand all icon in the tree grid header causes a crash

To Reproduce
demo app, tree grid plugin
click the expand all icon in the header

Expected behavior
All rows expand

Screenshots

TreeGridPlugin.java:339 Uncaught TypeError: icon_0_g$.isToggled_1_g$ is not a function
    at lambda$16_45_g$ (TreeGridPlugin.java:339:1)
    at TreeGridPlugin$lambda$16$Type_1_g$.accept_275_g$ [as accept_567_g$] (TreeGridPlugin.java:337:1)
    at Optional_1_g$.ifPresent_0_g$ [as ifPresent_4_g$] (Optional.java:71:1)
    at TreeGridPlugin_1_g$.expand_14_g$ [as expand_24_g$] (TreeGridPlugin.java:336:1)
    at TreeGridPlugin_1_g$.expandRow_2_g$ [as expandRow_5_g$] (TreeGridPlugin.java:151:1)
    at TreeGridPlugin_1_g$.lambda$14_49_g$ [as lambda$14_103_g$] (TreeGridPlugin.java:301:1)
    at TreeGridPlugin$lambda$14$Type_1_g$.accept_274_g$ [as accept_567_g$] (TreeGridPlugin.java:301:1)
    at ArrayList_1_g$.forEach_12_g$ [as forEach_35_g$] (ArrayList.java:176:1)
    at TreeGridPlugin_1_g$.expandAllRows_0_g$ [as expandAllRows_1_g$] (TreeGridPlugin.java:301:1)
    at TreeGridPlugin_1_g$.lambda$22_32_g$ [as lambda$22_69_g$] (TreeGridPlugin.java:531:1)
    at TreeGridPlugin$lambda$22$Type_1_g$.handleEvent_634_g$ [as handleEvent] (TreeGridPlugin.java:527:1)
lambda$16_45_g$ @ TreeGridPlugin.java:339
accept_275_g$ @ TreeGridPlugin.java:337
ifPresent_0_g$ @ Optional.java:71
expand_14_g$ @ TreeGridPlugin.java:336
expandRow_2_g$ @ TreeGridPlugin.java:151
lambda$14_49_g$ @ TreeGridPlugin.java:301
accept_274_g$ @ TreeGridPlugin.java:301
forEach_12_g$ @ ArrayList.java:176
expandAllRows_0_g$ @ TreeGridPlugin.java:301
lambda$22_32_g$ @ TreeGridPlugin.java:531
handleEvent_634_g$ @ TreeGridPlugin.java:527