code: func (g roleGraphEdgesTable) Find(user, host string) bool {
  	if host == "" {
  		host = "%"
  	}
  	key := user + "@" + host
  	if g.roleList == nil {
  		return false
  	}
  	_, ok := g.roleList[key]
  	return ok
  }
docs: // Find method is used to find role from table