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: completion.go
    path of file: ./repos/go-ethereum/internal/jsre
    
    the code of the file until where you have to start completion: // Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package jsre

import (
	"regexp"
	"sort"
	"strings"

	"github.com/dop251/goja"
)

// JS numerical token
var numerical = regexp.MustCompile(`^(NaN|-?((\d*\.\d+|\d+)([Ee][+-]?\d+)?|Infinity))$`)

// CompleteKeywords returns potential continuations for the given line. Since line is
// evaluated, callers need to make sure that evaluating line does not have side effects.
func (jsre *JSRE) CompleteKeywords(line string) []string {
	var results []string
	jsre.Do(func(vm *goja.Runtime) {
		results = getCompletions(vm, line)
	})
	return results
}

func getCompletions(vm *goja.Runtime, line string) (results []string) {
	parts := strings.Split(line, ".")
	if len(parts) == 0 {
		return nil
	}

	// Find the right-most fully named object in the line. e.g. if line = "x.y.z"
	// and "x.y" is an object, obj will reference "x.y
    
func getCompletions(vm *goja.Runtime, line string) (results []string) {
	parts := strings.Split(line, ".")
	if len(parts) == 0 {
		return nil
	}

	// Find the right-most fully named object in the line. e.g. if line = "x.y.z"
	// and "x.y" is an object, obj will reference "x.y".
	obj := vm.GlobalObject()
	for i := 0; i < len(parts)-1; i++ {
		if numerical.MatchString(parts[i]) {
			return nil
		}
		v := obj.Get(parts[i])
		if v == nil || goja.IsNull(v) || goja.IsUndefined(v) {
			return nil // No object was found
		}
		obj = v.ToObject(vm)
	}

	// Go over the keys of the object and retain the keys matching prefix.
	// Example: if line = "x.y.z" and "x.y" exists and has keys "zebu", "zebra"
	// and "platypus", then "x.y.zebu" and "x.y.zebra" will be added to results.
	prefix := parts[len(parts)-1]
	iterOwnAndConstructorKeys(vm, obj, func(k string) {
		if strings.HasPrefix(k, prefix) {
			if len(parts) == 1 {
				results = append(results, k)
			} else {
				results = append(results, strings.Join(parts[:len(parts)-1], ".")+"."+k)
			}
		}
	})

	// Append opening parenthesis (for functions) or dot (for objects)
	// if the line itself is the only completion.
	if len(results) == 1 && results[0] == line {
		// Accessing the property will cause it to be evaluated.
		// This can cause an error, e.g. in case of web3.eth.protocolVersion
		// which has been dropped from geth. Ignore the error for autocompletion
		// purposes.
		obj := SafeGet(obj, parts[len(parts)-1])
		if obj != nil {
			if _, isfunc := goja.AssertFunction(obj); isfunc {
				results[0] += "("
			} else {
				results[0] += "."
			}
		}
	}

	sort.Strings(results)
	return results
}