code: func (filters identityFilters) combine() identityFilter {
  	return func(identity api.PeerIdentityType) bool {
  		for _, f := range filters {
  			if !f(identity) {
  				return false
  			}
  		}
  		return true
  	}
  }
docs: // combine combines all identityFilters into a single identityFilter which only accepts identities
  // which all the original filters accept