How to use the mobiledoc-kit/utils/cursor/range function in mobiledoc-kit

// deselect any selected card because the cursor is no longer on a card
        if (this.selectedCard && !editor.range.isBlank) {
            this.deselectCard(this.selectedCard);
        }

        // if we have `code` or ~strike~ formatting to the left but not the right
        // then toggle the formatting - these formats should only be creatable
        // through the text expansions
        toggleSpecialFormatEditState(editor);

        // do not include the tail section if it's offset is 0
        // fixes triple-click unexpectedly selecting two sections for section-level formatting
        // https://github.com/bustle/mobiledoc-kit/issues/597
        if (direction === 1 && !isCollapsed && tail.offset === 0 && tail.section.prev) {
            let finalSection = tail.section.prev;
            let newRange = new MobiledocRange(head, finalSection.tailPosition());
            return editor.selectRange(newRange);
        }

        // pass the selected range through to the toolbar + menu components
        this.set('selectedRange', editor.range);
        this._scrollCursorIntoView();
    },

function renderIntoAndFocusTail(editorElement, treeFn, options={}) {
  let editor = renderInto(editorElement, treeFn, options);
  editor.selectRange(new Range(editor.post.tailPosition()));
  return editor;
}

run(editor) {
        if (editor.range.focusedPosition.section.type === 'list-item' &&
           editor.range.focusedPosition.section.prev &&
           editor.range.focusedPosition.offset === 0) {
          let prevSection = editor.range.focusedPosition.section.prev;
          let range = new Range(prevSection.headPosition(), prevSection.tailPosition());
          let markups = typeof prevSection.markupsInRange === 'function' ? prevSection.markupsInRange(range) : [];
          let markup = markups.find(item => {
            return item.attributes && item.attributes.href === NEW_LINE_HREF;
          });

          if (markup) {
            editor.run(postEditor => postEditor.toggleMarkup(markup, range));
          } else {
            return false;
          }
        } else {
          return false;
        }
      }
    });

run(editor) {
        let section = editor.range.focusedPosition.section;
        let range = new Range(section.headPosition(), section.tailPosition());
        let markups = typeof section.markupsInRange === 'function' ? section.markupsInRange(range) : [];
        let markup = markups.find(item => {
          return item.attributes && item.attributes.href === NEW_LINE_HREF;
        });
        if (section.type === 'list-item' &&
           editor.range.focusedPosition.section.next &&
           !markup) {
          editor.run(postEditor => {
            let markup = postEditor.builder.createMarkup('a', { href: NEW_LINE_HREF });
            postEditor.insertTextWithMarkup(section.tailPosition(), String.fromCharCode(8203), [markup]);
          });
        } else {
          return false;
        }
      }
    });

this.editor.editor.run(postEditor => {
        let range = new Range(this._lastActiveSection.headPosition(),this._lastActiveSection.tailPosition());
        postEditor.toggleSection(tag, range);
      });
      this.propertyDidChange('_lastActiveSection');