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: replica_split_load.go
    path of file: ./repos/cockroach/pkg/kv/kvserver
    
    the code of the file until where you have to start completion: // Copyright 2019 The Cockroach Authors.
//
// Use of this software is governed by the Business Source License
// included in the file licenses/BSL.txt.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this software will be governed
// by the Apache License, Version 2.0, included in the file
// licenses/APL.txt.

package kvserver

import (
	"con
    
func splitKeyPreCheck(rspan roachpb.RSpan, splitKey roachpb.Key) error {
	splitRKey, err := keys.Addr(splitKey)
	if err != nil {
		return err
	}

	// If the split key is equal to the start key of the range, it is treated as
	// a no-op in adminSplitWithDescriptor, however it is treated as an error
	// here because we shouldn't be suggesting split keys that are identical to
	// the start key of the range.
	if splitRKey.Equal(rspan.Key) {
		return errors.Errorf(
			"split key is equal to range start key (split_key=%s)",
			splitRKey)
	}

	return nil
}