# File lib/hammer_cli/options/normalizers.rb, line 29
        def format(val)
          return {} unless val.is_a?(String)
          return {} if val.empty?

          result = {}

          pair_re = '([^,=]+)=([^,\[]+|\[[^\[\]]*\])'
          full_re = "^((%s)[,]?)+$" % pair_re

          unless Regexp.new(full_re).match(val)
            raise ArgumentError, _("value must be defined as a comma-separated list of key=value")
          end

          val.scan(Regexp.new(pair_re)) do |key, value|
            value = value.strip
            value = value.scan(/[^,\[\]]+/) if value.start_with?('[')

            result[key.strip] = strip_value(value)
          end
          return result
        end