merge!

# File activesupport/lib/active_support/ordered_hash.rb, line 177
      def merge!(other_hash)
        if block_given?
          other_hash.each { |k, v| self[k] = key?(k) ? yield(k, self[k], v) : v }
        else
          other_hash.each { |k, v| self[k] = v }
        end
        self
      end