Initializes or doubles table size. If null, allocates in
accord with initial capacity target held in field threshold.
Otherwise, because we are using power-of-two expansion, the
elements from each bin must either stay at same index, or move
with a power of two offset in the new table.
Initializes or doubles table size. If null, allocates in accord with initial capacity target held in field threshold. Otherwise, because we are using power-of-two expansion, the elements from each bin must either stay at same index, or move with a power of two offset in the new table.
@return the table