small refactor

Author: TonioMacaronio

web3swift/PrecompiledContracts/ERC721/Web3+ERC721.swift

@@ -11,7 +11,7 @@ import EthereumAddress
 
 // This namespace contains functions to work with ERC721 tokens.
 // can be imperatively read and saved
-public class ERC721: IERC165 {
+public class ERC721 {
 
     @available(*, deprecated, renamed: "transactionOptions")
     public var options: Web3Options = .init()
@@ -178,6 +178,10 @@ public class ERC721: IERC165 {
         return tx
     }
 
+}
+
+extension ERC721: IERC165 {
+    
     public func supportsInterface(interfaceID: [UInt8]) throws -> Bool {
         let contract = self.contract
         var transactionOptions = TransactionOptions()