# File lib/rhc/vendor/parseconfig.rb, line 121
      def add(param_name, value)
        if value.class == Hash
          if self.params.has_key?(param_name)
            if self.params[param_name].class == Hash
              self.params[param_name].merge!(value)
            elsif self.params.has_key?(param_name)
              if self.params[param_name].class != value.class
                raise ArgumentError, "#{param_name} already exists, and is of different type!"
              end
            end
          else
            self.params[param_name] = value
          end
          if ! self.groups.include?(param_name)
            self.groups.push(param_name)
          end
        else
          self.params[param_name] = value
        end
      end