static getEnum(param) {
    if (!('pattern' in this.route)) {
      throw new Error('getEnum() requires route to have a .pattern property')
    }
    const enumeration = getEnum(this.route.pattern, param)
    if (!Array.isArray(enumeration)) {
      throw new Error(
        `Could not extract enum for param ${param} from pattern ${this.route.pattern}`,
      )
    }
    return enumeration
  }
Extract an array of allowed values from this service's route pattern
for a given route parameter

@param {string} param The name of a param in this service's route pattern
@returns {string[]} Array of allowed values for this param