eclosure

# File actionpack/lib/action_dispatch/journey/nfa/transition_table.rb, line 115
        def eclosure(t)
          stack = Array(t)
          seen  = {}
          children = []

          until stack.empty?
            s = stack.pop
            next if seen[s]

            seen[s] = true
            children << s

            stack.concat(inverted[s][nil])
          end

          children.uniq
        end