entity

type Entity interface {
	// ID retrieves the id of this entity.
	ID() string
	// AddComponent adds a component to the entity.  Returns an error if the component type has already been added.
	AddComponent(components.Component) error
	// RemoveComponent removes a component from the entity.  If the component type is not already attached an error will be returned.
	RemoveComponent(string) error
	// ReplaceComponent replaces an existing component with a new one of the same type.
	ReplaceComponent(c components.Component) error
	// Component retrieves a component based on its component type.
	Component(string) components.Component
	// Retrieves a list of component types that have been attached to this entity.
	ComponentTypes() []string
}