How to use the element-ui/src/utils/dom.removeClass function in element-ui

const draggingNodeCopy = { data: draggingNode.node.data };
          if (dropType !== 'none') {
            draggingNode.node.remove();
          }
          if (dropType === 'before') {
            dropNode.node.parent.insertBefore(draggingNodeCopy, dropNode.node);
          } else if (dropType === 'after') {
            dropNode.node.parent.insertAfter(draggingNodeCopy, dropNode.node);
          } else if (dropType === 'inner') {
            dropNode.node.insertChild(draggingNodeCopy);
          }
          if (dropType !== 'none') {
            this.store.registerNode(draggingNodeCopy);
          }

          removeClass(dropNode.$el, 'is-drop-inner');

          this.$emit('node-drag-end', draggingNode.node, dropNode.node, dropType, event);
          if (dropType !== 'none') {
            this.$emit('node-drop', draggingNode.node, dropNode.node, dropType, event);
          }
        }
        if (draggingNode && !dropNode) {
          this.$emit('node-drag-end', draggingNode.node, null, dropType, event);
        }

        dragState.showDropIndicator = false;
        dragState.draggingNode = null;
        dragState.dropNode = null;
        dragState.allowDrop = true;
      });
    },

handleSortClick (event, column, givenOrder) {
      event.stopPropagation();
      let order = givenOrder || this.toggleOrder(column.order);

      let target = event.target;
      while (target && target.tagName !== 'TH') {
        target = target.parentNode;
      }

      if (target && target.tagName === 'TH') {
        if (hasClass(target, 'noclick')) {
          removeClass(target, 'noclick');
          return;
        }
      }

      if (!column.sortable) return;

      const states = this.store.states;
      let sortProp = states.sortProp;
      let sortOrder;
      const sortingColumn = states.sortingColumn;

      if (sortingColumn !== column || (sortingColumn === column && sortingColumn.order === null)) {
        if (sortingColumn) {
          sortingColumn.order = null;
        }
        states.sortingColumn = column;

focusing(val) {
      if (val) {
        addClass(this.referenceElm, 'focusing');
      } else {
        removeClass(this.referenceElm, 'focusing');
      }
    }
  },

raf(() => {
        const rows = this.$el.querySelectorAll('.el-table__row')
        const oldRow = rows[oldVal]
        const newRow = rows[newVal]
        if (oldRow) {
          removeClass(oldRow, 'hover-row')
        }
        if (newRow) {
          addClass(newRow, 'hover-row')
        }
      })
    }

"store.states.hoverRow"(newVal, oldVal) {
      if (!this.store.states.isComplex) return;
      const rows = this.$el.querySelectorAll(".el-table__row");
      const oldRow = rows[oldVal];
      const newRow = rows[newVal];
      if (oldRow) {
        removeClass(oldRow, "hover-row");
      }
      if (newRow) {
        addClass(newRow, "hover-row");
      }
    }
  },

afterLeave(el.instance, _ => {
        if (!el.instance.hiding) return;
        el.domVisible = false;
        const target = binding.modifiers.fullscreen || binding.modifiers.body
          ? document.body
          : el;
        removeClass(target, 'el-loading-parent--relative');
        removeClass(target, 'el-loading-parent--hidden');
        el.instance.hiding = false;
      }, 300, true);
      el.instance.visible = false;

'store.states.currentRow'(newVal, oldVal) {
      if (!this.highlight) return;
      const el = this.$el;
      if (!el) return;
      const data = this.store.states.data;
      const tr = el.querySelector('tbody').children;
      const rows = [].filter.call(tr, row => hasClass(row, 'el-table__row'));
      const oldRow = rows[data.indexOf(oldVal)];
      const newRow = rows[data.indexOf(newVal)];
      if (oldRow) {
        removeClass(oldRow, 'current-row');
      } else if (rows) {
        [].forEach.call(rows, row => removeClass(row, 'current-row'));
      }
      if (newRow) {
        addClass(newRow, 'current-row');
      }
    }
  },

setTimeout(function() {
            removeClass(columnEl, 'noclick');
          }, 0);
        };

Vue.nextTick(() => {
        if (binding.modifiers.fullscreen) {
          el.originalPosition = getStyle(document.body, 'position');
          el.originalOverflow = getStyle(document.body, 'overflow');
          el.maskStyle.zIndex = PopupManager.nextZIndex();

          addClass(el.mask, 'is-fullscreen');
          insertDom(document.body, el, binding);
        } else {
          removeClass(el.mask, 'is-fullscreen');

          if (binding.modifiers.body) {
            el.originalPosition = getStyle(document.body, 'position');

            ['top', 'left'].forEach(property => {
              const scroll = property === 'top' ? 'scrollTop' : 'scrollLeft';
              el.maskStyle[property] = el.getBoundingClientRect()[property] +
                document.body[scroll] +
                document.documentElement[scroll] -
                parseInt(getStyle(document.body, `margin-${ property }`), 10) +
                'px';
            });
            ['height', 'width'].forEach(property => {
              el.maskStyle[property] = el.getBoundingClientRect()[property] + 'px';
            });

raf(() => {
        const rows = this.$el.querySelectorAll('.el-table__row');
        const oldRow = rows[oldVal];
        const newRow = rows[newVal];
        if (oldRow) {
          removeClass(oldRow, 'hover-row');
        }
        if (newRow) {
          addClass(newRow, 'hover-row');
        }
      });
    }