# Initialize the command mentity.
	#
	# If not already set, tries to find the `mentity` from the `mentity_name`.
	#
	# This function try to match `mentity_name` both as a `full_name` and
	# `name`.
	#
	# Return states:
	# * `CmdSuccess`: everything was ok;
	# * `ErrorMEntityNoName`: no `mentity` and no `mentity_name` provided;
	# * `ErrorMEntityNotFound`: no mentity for `mentity_name`;
	# * `ErrorMEntityConflict`: `mentity_name` was a non-qualified name that
	#   returns more than one MEntity.
	fun init_mentity: CmdMessage do
		if mentity != null then
			if mentity_name == null then mentity_name = mentity.as(not null).full_name
			return new CmdSuccess
		end

		var mentity_name = self.mentity_name
		if mentity_name == null or mentity_name.is_empty then return new ErrorMEntityNoName

		mentity = model.mentity_by_full_name(mentity_name)
		if mentity == null then
			var mentities = model.mentities_by_name(mentity_name)
			if mentities.is_empty then
				var suggest = model.find(mentity_name, 3)
				return new ErrorMEntityNotFound(mentity_name, suggest)
			else if mentities.length > 1 then
				return new ErrorMEntityConflict(mentity_name, mentities)
			end
			mentity = mentities.first
		end
		return new CmdSuccess
	end