def has_key?(key)
      hashed_key = hash_key(key)
      unless (entry = @btree.get(hashed_key))
        return false
      end

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

      false
    end
def has_key?(key)
      hashed_key = hash_key(key)
      unless (entry = @btree.get(hashed_key))
        return false
      end

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

      false
    end
Check if the is a value stored for the given key.
 @param key [Integer or String]
 @return [TrueClass or FalseClass]