-- This module implements {{error}}.  local p = {}  local HtmlBuilder = require('Module:HtmlBuilder')  local function _error(args)  local message = args.message or args[1] or error('no message specified', 2)  message = tostring(message)  local tag = mw.ustring.lower(tostring(args.tag))   -- Work out what html tag we should use.  if not (tag == 'p' or tag == 'span' or tag == 'div') then  tag = 'strong'  end   -- Generate the html.  local root = HtmlBuilder.create(tag)  root  .addClass('error')  .wikitext(message)   return tostring(root) end  function p.error(frame)  local args  if frame == mw.getCurrentFrame() then  -- We're being called via #invoke. The args are passed through to the module  -- from the template page, so use the args that were passed into the template.  args = frame.args  else  -- We're being called from another module or from the debug console, so assume  -- the args are passed in directly.  args = frame  end  -- if the message parameter is present but blank, change it to nil so that Lua will  -- consider it false.  if args.message == "" then  args.message = nil  end  return _error(args) end  return p