code: func (c *Context) GlobalIsSet(name string) bool {
  	ctx := c
  	if ctx.parentContext != nil {
  		ctx = ctx.parentContext
  	}
  
  	for ; ctx != nil; ctx = ctx.parentContext {
  		if ctx.IsSet(name) {
  			return true
  		}
  	}
  	return false
  }
docs: // GlobalIsSet determines if the global flag was actually set