URLRequestBuilder-7.swift

class URLRequestBuilder {

  var adapters: [RequestAdapter] = []

  // ...rest of properties...

  @discardableResult
  func add(adapter: RequestAdapter?) -> URLRequestBuilder {
      guard let adapter = adapter else { return self }
      adapters.append(adapter)
      return self
  }
  
  // ...rest of sets...

  func build() throws -> URLRequest {
      do {

        try adapters.forEach {
            urlRequest = try $0.adapt(urlRequest)
        }

        // rest of code...

          return urlRequest
      } catch {
          throw APIError.requestBuilderFailed
      }
  }
}