# File lib/mail/message.rb, line 1051
    def body=(value)
      case
      when value == nil
        @body = Mail::Body.new('')
      when @body && !@body.parts.empty?
        @body << Mail::Part.new(value)
      else
        @body = Mail::Body.new(value)
      end
      add_encoding_to_body
    end