如何确定FieldDeclarationSyntax的类型是否为Roslyn中的接口？

using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp.Syntax;

// 假设有一个FieldDeclarationSyntax对象名为fieldDeclarationSyntax

var fieldSymbol = semanticModel.GetDeclaredSymbol(fieldDeclarationSyntax.Declaration.Variables.First()) as IFieldSymbol;
var fieldTypeSymbol = fieldSymbol?.Type;

bool isInterface = fieldTypeSymbol?.TypeKind == TypeKind.Interface;

var compilation = await document.Project.GetCompilationAsync();
var syntaxTree = await document.GetSyntaxTreeAsync();
var semanticModel = compilation.GetSemanticModel(syntaxTree);