static get properties() {
    return {
      /**
       * Step status, one of: "untouched", "entered", "left", "skipped".
       */
      status: {
        type: String,
        reflect: true,
      },
      /**
       * The funtion which us run to check if this step can be transitioned to.
       * Takes lion-steps data as a first argument `myConditionFunc(data)`.
       */
      condition: {
        attribute: false,
      },
      /**
       * Allows to invert condition function result.
       */
      invertCondition: {
        type: Boolean,
        reflect: true,
        attribute: 'invert-condition',
      },
      /**
       * Allows transition to step only in forward direction. Skips it if transitioned back.
       * May be useful if the step is only showing some messages and does data loading and
       * then makes transition to next step automatically.
       */
      forwardOnly: {
        type: Boolean,
        reflect: true,
        attribute: 'forward-only',
      },
      /**
       * If set this step will be the initially enabled step
       * There should be only ONE intial step in each steps
       */
      initialStep: {
        type: Boolean,
        reflect: true,
        attribute: 'initial-step',
      },
    };
  }
`LionStep` is one of many in a LionSteps Controller

@customElement lion-step
@extends {LitElement}