NServiceBus.ConcreteProxyCreator.BuildCustomAttribute C# (CSharp) Method

        static CustomAttributeBuilder BuildCustomAttribute(object customAttribute)
        {
            ConstructorInfo longestCtor = null;
            // Get constructor with the largest number of parameters
            foreach (var cInfo in customAttribute.GetType().GetConstructors().
                Where(cInfo => longestCtor == null || longestCtor.GetParameters().Length < cInfo.GetParameters().Length))
            {
                longestCtor = cInfo;
            }

            if (longestCtor == null)
            {
                return null;
            }

            // For each constructor parameter, get corresponding (by name similarity) property and get its value
            var args = new object[longestCtor.GetParameters().Length];
            var position = 0;
            foreach (var consParamInfo in longestCtor.GetParameters())
            {
                var attrPropInfo = customAttribute.GetType().GetProperty(consParamInfo.Name, BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);
                if (attrPropInfo != null)
                {
                    args[position] = attrPropInfo.GetValue(customAttribute, null);
                }
                else
                {
                    args[position] = null;
                    var attrFieldInfo = customAttribute.GetType().GetField(consParamInfo.Name, BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.IgnoreCase);
                    if (attrFieldInfo == null)
                    {
                        if (consParamInfo.ParameterType.IsValueType)
                        {
                            args[position] = Activator.CreateInstance(consParamInfo.ParameterType);
                        }
                    }
                    else
                    {
                        args[position] = attrFieldInfo.GetValue(customAttribute);
                    }
                }
                ++position;
            }

            var propList = new List<PropertyInfo>();
            var propValueList = new List<object>();
            foreach (var attrPropInfo in customAttribute.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance))
            {
                if (!attrPropInfo.CanWrite)
                {
                    continue;
                }
                object defaultValue = null;
                var defaultAttributes = attrPropInfo.GetCustomAttributes(typeof(DefaultValueAttribute), true);
                if (defaultAttributes.Length > 0)
                {
                    defaultValue = ((DefaultValueAttribute) defaultAttributes[0]).Value;
                }
                var value = attrPropInfo.GetValue(customAttribute, null);
                if (value == defaultValue)
                {
                    continue;
                }
                propList.Add(attrPropInfo);
                propValueList.Add(value);
            }
            return new CustomAttributeBuilder(longestCtor, args, propList.ToArray(), propValueList.ToArray());
        }