params_hash_has_key?

# File actionpack/lib/action_dispatch/http/param_builder.rb, line 175
      def params_hash_has_key?(hash, key)
        return false if key.include?("[]")

        key.split(/[\[\]]+/).inject(hash) do |h, part|
          next h if part == ""
          return false unless params_hash_type?(h) && h.key?(part)
          h[part]
        end

        true
      end