code: function linkState(component, key, eventPath) {
      var path = key.split('.'),
        cache = component.__lsc || (component.__lsc = {});
      return (
        cache[key + eventPath] ||
        (cache[key + eventPath] = function(e) {
          var t = (e && e.target) || this,
            state = {},
            obj = state,
            v = typeof eventPath === 'string' ? dlv(e, eventPath) : t.nodeName ? (t.type.match(/^che|rad/) ? t.checked : t.value) : e,
            i = 0;
  
          for (; i < path.length - 1; i++) {
            obj = obj[path[i]] || (obj[path[i]] = (!i && component.state[path[i]]) || {});
          }
  
          obj[path[i]] = v;
          component.setState(state);
        })
      );
    }
docs: Create an Event handler function that sets a given state property.
  @param {Component} component	The component whose state should be updated
  @param {string} key				A dot-notated key path to update in the component's state
  @param {string} eventPath		A dot-notated key path to the value that should be retrieved from the Event or component
  @returns {function} linkedStateHandler