Fix check condition

Author: lmcmz

Sources/Codeable/FlowArgument+Decode.swift

@@ -131,11 +131,11 @@ extension Flow.Argument: FlowDecodable {
                 return nil
             }
 
-            guard result.isEmpty, let first = result.first else {
+            if result.isEmpty {
                 return [String: Any]()
             }
 
-            switch first.key.type {
+            switch result.first?.key.type {
             case .int:
                 return result.decode(Int.self)
             case .uint:

Sources/Models/FlowScript.swift

@@ -89,14 +89,14 @@ extension Flow.ScriptResponse: FlowDecodable {
     }
 
     public func decode<T: Decodable>(_: T.Type) throws -> T {
-        guard let result: T = try? fields?.decode() else {
+        guard let result: T = try fields?.decode() else {
             throw Flow.FError.decodeFailure
         }
         return result
     }
 
     public func decode<T: Decodable>() throws -> T {
-        guard let result: T = try? fields?.decode() else {
+        guard let result: T = try fields?.decode() else {
             throw Flow.FError.decodeFailure
         }
         return result