resolve () {
    const id = this.parent?.resource?.data?.relationships?.[this.key]?.data?.id

    if (id === undefined) {
      return null
    }

    return this.findInclude(id)
  }
/**
   * Resolves the model of the relationship
   * @returns {null|Model}
   */
Resolves the model of the relationship
@returns {null|Model}
Resolves the model of the relationship @returns { null|Model }
resolve () {
    const id = this.parent?.resource?.data?.relationships?.[this.key]?.data?.id
    if (id === undefined) {
      return null
    }
    return this.findInclude(id)
  }
resolve ( ) { const id = this . parent ?. resource ?. data ?. relationships ?. [ this . key ] ?. data ?. id if ( id === undefined ) { return null } return this . findInclude ( id ) }
Resolves the model of the relationship
 @returns {null|Model}
Resolves the model of the relationship @returns { null|Model }