func (e *Environment) Set(name string, val Object) Object {
	e.store[name] = val
	return val
}
Set sets a key to an Environment's store by name
package object
type Environment struct {
	store map[string]Object
	outer *Environment
}
func (e *Environment) Get(name string) (Object, bool) {
	obj, ok := e.store[name]
	if !ok && e.outer != nil {
		obj, ok = e.outer.Get(name)
	}
	return obj, ok
}