Can be used in UnitTests to access private members over `dynamic` keyword.

AccessPrivateWrapper.cs

public class AccessPrivateWrapper : DynamicObject
{
    /// <summary>
    /// The object we are going to wrap
    /// </summary>
    private readonly object _instance;

    /// <summary>
    /// Specify the flags for accessing members
    /// </summary>
    private const BindingFlags Flags = BindingFlags.NonPublic | BindingFlags.Instance
                                       | BindingFlags.Static | BindingFlags.Public;

    /// <summary>
    /// Create a simple private wrapper
    /// </summary>
    public AccessPrivateWrapper(object instance)
    {
        this._instance = instance;
    }

    /// <summary>
    /// Try invoking a method
    /// </summary>
    public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
    {
        // TODO: Check if one of args is null
        var types = args.Select(a => a.GetType()).ToArray();

        var methodInfo = this._instance.GetType().GetMethod
            (binder.Name, Flags, null, types, null);

        if (methodInfo != null)
        {
            result = methodInfo.Invoke(this._instance, args);
            return true;
        }

        return base.TryInvokeMember(binder, args, out result);
    }

    /// <summary>
    /// Tries to get a property or field with the given name
    /// </summary>
    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        //Try getting a property of that name
        var propertyInfo = this._instance.GetType().GetProperty(binder.Name, Flags);

        if (propertyInfo != null)
        {
            result = propertyInfo.GetValue(this._instance, null);
            return true;
        }

        //Try getting a field of that name
        var fieldInfo = this._instance.GetType().GetField(binder.Name, Flags);
        if (fieldInfo != null)
        {
            result = fieldInfo.GetValue(this._instance);
            return true;
        }

        return base.TryGetMember(binder, out result);
    }

    /// <summary>
    /// Tries to set a property or field with the given name
    /// </summary>
    public override bool TrySetMember(SetMemberBinder binder, object value)
    {
        var propertyInfo = this._instance.GetType().GetProperty(binder.Name, Flags);
        if (propertyInfo != null)
        {
            propertyInfo.SetValue(this._instance, value, null);
            return true;
        }

        var fieldInfo = this._instance.GetType().GetField(binder.Name, Flags);
        if (fieldInfo != null)
        {
            fieldInfo.SetValue(this._instance, value);
            return true;
        }

        return base.TrySetMember(binder, value);
    }
}