def extended_message
    @extended_message ||= begin
      sections = []
      
      sections << details_section unless details_section.nil?
      sections << context_section unless context_section.nil?
      
      joined = sections.join "\n\n"
    end
  end
def extended_message
    @extended_message ||= begin
      sections = []
      
      sections << details_section unless details_section.nil?
      sections << context_section unless context_section.nil?
      
      joined = sections.join "\n\n"
    end
  end
Return the extended message, rendering if necessary (cached after first
 call).

 @return [String]
   Will be empty if there is no extended message.