code: def remove_pattern(self, pattern):
          
  
          for index, node in enumerate(self.root_node.children):
              if node.name != pattern:
                  continue
  
              LOGGER.debug("> Removing '{0}' at '{1}' index.".format(pattern, index))
  
              self.beginRemoveRows(self.get_node_index(self.root_node), index, index)
              pattern_node = self.root_node.child(index)
              self.root_node.remove_child(index)
              self.endRemoveRows()
              self.pattern_removed.emit(pattern_node)
              return True
docs: Removes given pattern from the Model.
  
          :param pattern: Pattern.
          :type pattern: unicode
          :return: Method success.
          :rtype: bool