Add some experimental brush commands.

/br set <shape> <radius> <pattern>
/br deform <shape> <expression>
/br scatter <shape> <density> <generator>
/br apply <shape> <generator>

<shape> can be: cuboid, cyl[inder], sphere

<density> is 0-100

<generator> can be:
forest|tree <type>
item <item>[:<data>] (ONLY WORKS ON FORGE)

Examples:

/br deform cuboid 5 y-=0.2
/br scatter sphere 5 100 minecraft:dye:15

worldedit-core/src/main/java/com/sk89q/worldedit/LocalSession.java

@@ -613,7 +613,6 @@ public class LocalSession {
      * @return the tool, or {@code null}
      * @throws InvalidToolBindException if the item can't be bound to that item
      */
-    @Nullable
     public BrushTool getBrushTool(int item) throws InvalidToolBindException {
         Tool tool = getTool(item);