Pass QuoteRequestor via SwapQuoteOpts not ctor arg

Addresses review comment https://github.com/0xProject/0x-monorepo/pull/2541#discussion_r405900525

packages/asset-swapper/src/swap_quoter.ts

@@ -148,12 +148,7 @@ export class SwapQuoter {
      *
      * @return  An instance of SwapQuoter
      */
-    constructor(
-        supportedProvider: SupportedProvider,
-        orderbook: Orderbook,
-        options: Partial<SwapQuoterOpts> = {},
-        quoteRequestor?: QuoteRequestor,
-    ) {
+    constructor(supportedProvider: SupportedProvider, orderbook: Orderbook, options: Partial<SwapQuoterOpts> = {}) {
         const {
             chainId,
             expiryBufferMs,
@@ -176,7 +171,7 @@ export class SwapQuoter {
         this._devUtilsContract = new DevUtilsContract(this._contractAddresses.devUtils, provider);
         this._protocolFeeUtils = new ProtocolFeeUtils(constants.PROTOCOL_FEE_UTILS_POLLING_INTERVAL_IN_MS);
         this._orderStateUtils = new OrderStateUtils(this._devUtilsContract);
-        this._quoteRequestor = quoteRequestor || new QuoteRequestor(this.rfqtMakerEndpoints);
+        this._quoteRequestor = options.quoteRequestor || new QuoteRequestor(this.rfqtMakerEndpoints);
         const sampler = new DexOrderSampler(
             new IERC20BridgeSamplerContract(this._contractAddresses.erc20BridgeSampler, this.provider, {
                 gas: samplerGasLimit,

packages/asset-swapper/src/types.ts

@@ -3,6 +3,7 @@ import { SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 
 import { GetMarketOrdersOpts } from './utils/market_operation_utils/types';
+import { QuoteRequestor } from './utils/quote_requestor';
 
 /**
  * expiryBufferMs: The number of seconds to add when calculating whether an order is expired or not. Defaults to 300s (5m).
@@ -219,6 +220,7 @@ export interface SwapQuoterOpts extends OrderPrunerOpts {
     liquidityProviderRegistryAddress?: string;
     rfqtTakerApiKeyWhitelist?: string[];
     rfqtMakerEndpoints?: string[];
+    quoteRequestor?: QuoteRequestor;
 }
 
 /**