docs: def _create_entry(self, location, element, unique=True, delete_element=False):
          """
          Create an entry located at ``location``.
          
          Args:
              location: String or :class:`LocationDescriptor` to describe a "separator location" (i.e. dir1/dir2/dir3 for
                  instance).
              element: Element to store at the location.
              unique: ``True`` means that the element to store **must** be unique and that the corresponding node doesn't already exist.
              delete_element: In case the element must not be unique, delete or not the existing element at
                  the ``location`` if it exist?
          
          Returns:
              The created node with the element.
              
          Raises:
              A ``RuntimeError`` is raised if leaf node already exists and ``unique`` is set to ``True``.
  
          Note:
              Non existing linking node (i.e. non leaf nodes) are created on the fly.
          """
          loc_descriptor = self._get_location_descriptor(location)
  
          # find parent node
          parent_node = self._root_node
          if loc_descriptor.nbr_of_sub_locations() > 1:
              parent_node = self._get_node(loc_descriptor.get_sub_location_descriptor(), create_non_existing_nodes=True)
  
          # find child node if it exist
          last_location = loc_descriptor.last_sub_location()
          child_node = parent_node.get_child_node_or_default(last_location, None)
          if child_node is None:
              # create node
              child_node = TreeMapNode(element)
              parent_node.set_child_node(last_location, child_node)
              self._nbr_of_nodes += 1
          else:
              # child node exist
              if unique:
                  raise RuntimeError("Node corresponding to the location '%s' already exist!" % loc_descriptor.to_string())
              elif delete_element:
                  child_node.delete_element()
              child_node.set_element(element)
  
          return child_node