def [](key)
      hashed_key = hash_key(key)
      unless (entry = @btree.get(hashed_key))
        return nil
      end

      if entry.is_a?(PEROBS::Array)
        entry.each do |ae|
          return ae.value if ae.key == key
        end
      else
        return entry.value if entry.key == key
      end

      nil
    end
def [](key)
      hashed_key = hash_key(key)
      unless (entry = @btree.get(hashed_key))
        return nil
      end

      if entry.is_a?(PEROBS::Array)
        entry.each do |ae|
          return ae.value if ae.key == key
        end
      else
        return entry.value if entry.key == key
      end

      nil
    end
Retrieve the value for the given key. If no value for the key is found
 nil is returned.
 @param key [Integer or String]
 @return [Any PEROBS storable object]