You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: rrstrategy.go
    path of file: ./repos/mgmt/etcd/scheduler
    
    the code of the file until where you have to start completion: // Mgmt
// Copyright (C) 2013-2024+ James Shubin and the project contributors
// Written by James Shubin <james@shubin.ca> and the project contributors
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//
// Additional permission under GNU GPL version 3 section 7
//
// If you modify this program, or any covered work, by linking or combining it
// with embedded mcl code and modules (and that the embedded mcl code and
// modules which link with this program, contain a copy of their source code in
// the authoritative form) containing parts covered by the terms
    
func (obj *rrStrategy) Schedule(hostnames map[string]string, opts *schedulerOptions) ([]string, error) {
	if len(hostnames) <= 0 {
		return nil, fmt.Errorf("strategy: cannot schedule from zero hosts")
	}
	if opts.maxCount <= 0 {
		return nil, fmt.Errorf("strategy: cannot schedule with a max of zero")
	}

	// always get a deterministic list of current hosts first...
	sortedHosts := []string{}
	for key := range hostnames {
		sortedHosts = append(sortedHosts, key)
	}
	sort.Strings(sortedHosts)

	if obj.hosts == nil {
		obj.hosts = []string{} // initialize if needed
	}

	// add any new hosts we learned about, to the end of the list
	for _, x := range sortedHosts {
		if !util.StrInList(x, obj.hosts) {
			obj.hosts = append(obj.hosts, x)
		}
	}

	// remove any hosts we previouly knew about from the list
	for ix := len(obj.hosts) - 1; ix >= 0; ix-- {
		if !util.StrInList(obj.hosts[ix], sortedHosts) {
			// delete entry at this index
			obj.hosts = append(obj.hosts[:ix], obj.hosts[ix+1:]...)
		}
	}

	// get the maximum number of hosts to return
	max := len(obj.hosts)    // can't return more than we have
	if opts.maxCount < max { // found a smaller limit
		max = opts.maxCount
	}

	result := []string{}
	// now return the number of needed hosts from the list
	for i := 0; i < max; i++ {
		result = append(result, obj.hosts[i])
	}

	return result, nil
}