Is .NET assembly optimized

AssemblyExtensions.cs

using System.ComponentModel;
using System.Diagnostics;
using System.Reflection;

[EditorBrowsable(EditorBrowsableState.Never)]
internal static class AssemblyExtensions
{
    /// <summary>
    /// Whether the assembly was compiled with the optimize+ flag
    /// </summary>
    /// <param name="asm">The assemlby to verify the optimization flag</param>
    /// <returns>
    /// true if no <see cref="DebuggableAttribute"/> exists or
    /// <see cref="DebuggableAttribute.IsJITOptimizerDisabled"/> is false,
    /// otherwise, false.
    /// </returns>
    public static bool IsOptimized(this Assembly asm)
    {
        var att = asm.GetCustomAttribute<DebuggableAttribute>();
        return att == null || att.IsJITOptimizerDisabled == false;
    }
}