Shared exchange functionality (#214)

CryptoExchange.Net/SharedApis/Interfaces/Rest/Futures/IFuturesTickerRestClient.cs

@@ -0,0 +1,34 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace CryptoExchange.Net.SharedApis
+{
+    /// <summary>
+    /// Client for requesting ticker info for futures symbols
+    /// </summary>
+    public interface IFuturesTickerRestClient : ISharedClient
+    {
+        /// <summary>
+        /// Futures get ticker request options
+        /// </summary>
+        EndpointOptions<GetTickerRequest> GetFuturesTickerOptions { get; }
+        /// <summary>
+        /// Get ticker info for a specific futures symbol
+        /// </summary>
+        /// <param name="request">Request info</param>
+        /// <param name="ct">Cancellation token</param>
+        Task<ExchangeWebResult<SharedFuturesTicker>> GetFuturesTickerAsync(GetTickerRequest request, CancellationToken ct = default);
+
+        /// <summary>
+        /// Futures get tickers request options
+        /// </summary>
+        EndpointOptions<GetTickersRequest> GetFuturesTickersOptions { get; }
+        /// <summary>
+        /// Get ticker info for aall futures symbols
+        /// </summary>
+        /// <param name="request">Request info</param>
+        /// <param name="ct">Cancellation token</param>
+        Task<ExchangeWebResult<IEnumerable<SharedFuturesTicker>>> GetFuturesTickersAsync(GetTickersRequest request, CancellationToken ct = default);
+    }
+}