The icon to show within each item within the tree that helps show that
there are child items.
NOTE: This will override the rightAddon prop if defined on each item by
default so they can't be used. If the expanderLeft prop is enabled, the
leftAddon will be overridden instead.
Optional expanderLeft
expanderLeft:boolean
Boolean if the expander icon should appear to the left instead of the
right.
The icon to show within each item within the tree that helps show that there are child items.
NOTE: This will override the
rightAddonprop if defined on each item by default so they can't be used. If theexpanderLeftprop is enabled, theleftAddonwill be overridden instead.