fetch

Same as Hash#fetch where the key passed as argument can be either a string or a symbol:

counters = HashWithIndifferentAccess.new
counters[:foo] = 1

counters.fetch("foo")          # => 1
counters.fetch(:bar, 0)        # => 0
counters.fetch(:bar) {|key| 0} # => 0
counters.fetch(:zoo)           # => KeyError: key not found: "zoo"