The specified Type must be a ComponentSystemGroup. Updating in a group means this system will be automatically updated by the specified ComponentSystemGroup when the group is updated. The system may order itself relative to other systems in the group with UpdateBefore and UpdateAfter. This ordering takes effect when the system group is sorted. If the optional OrderFirst parameter is set to true, this system will act as if it has an implicit [UpdateBefore] targeting all other systems in the group that do "not" have OrderFirst=true, but it may still order itself relative to other systems with OrderFirst=true. If the optional OrderLast parameter is set to true, this system will act as if it has an implicit [UpdateAfter] targeting all other systems in the group that do "not" have OrderLast=true, but it may still order itself relative to other systems with OrderLast=true. An UpdateInGroup attribute with both OrderFirst=true and OrderLast=true is invalid, and will throw an exception.
[AttributeUsage(AttributeTargets.Class|AttributeTargets.Struct)]public class UpdateInGroupAttribute : Attribute