create
Create a new hashed set bin with the given level, local size, total recursive number of elements, hash, bit vector, and either the bin union kind or nil. Initialize each sub-bin to the empty bin at level + 1.
Return
A new hashed set bin with empty linear sub-bins.
Parameters
level
The tree level at which this hashed bin occurs.
local
The number of slots to allocate.
bit
The bit vector indicating which hash values are present.