Poor man's PrivateObject implementation for .NET Standard

PrivateObject.cs

public class PrivateObject
{
    private readonly object o;

    public PrivateObject(object o)
    {
        this.o = o;
    }

    public object Invoke(string methodName, params object[] args)
    {
        var methodInfo = o.GetType().GetMethod(methodName, BindingFlags.NonPublic | BindingFlags.Instance);
        if (methodInfo == null)
        {
            throw new Exception($"Method'{methodName}' not found is class '{o.GetType()}'");
        }
        return methodInfo.Invoke(o, args);
    }
}