Container for multiple behaviors that returns the result of the first child behavior with non-zero acceleration. Container for multiple behaviors that returns the result of the first child behavior with non-zero acceleration. Appends a steering behavior as a child of this container. Returns the behavior at the position in the pool referred to by index, or null if no behavior was found. Returns how many behaviors are added. Removed the behavior at the position in the pool referred to by index. If a behavior's acceleration is lower than this threshold, the container considers it has an acceleration of zero.