docs: def set_raw(self,text):
          """
          Sets the text of the raw element (or creates the layer if does not exist)
          @param text: text of the raw layer
          @type text: string
          """
          node_raw = self.root.find('raw')
          if node_raw is None:
              node_raw = etree.Element('raw')
              self.root.insert(0,node_raw)
          node_raw.text = etree.CDATA(text)