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: builtin_number.go
    path of file: ./repos/hoverfly/vendor/github.com/robertkrimen/otto
    
    the code of the file until where you have to start completion: package otto

import (
	"math"
	"strconv"
)

// Number

    
func builtinNumber_toString(call FunctionCall) Value {
	// Will throw a TypeError if ThisObject is not a Number
	value := call.thisClassObject("Number").primitiveValue()
	radix := 10
	radixArgument := call.Argument(0)
	if radixArgument.IsDefined() {
		integer := toIntegerFloat(radixArgument)
		if integer < 2 || integer > 36 {
			panic(call.runtime.panicRangeError("toString() radix must be between 2 and 36"))
		}
		radix = int(integer)
	}
	if radix == 10 {
		return toValue_string(value.string())
	}
	return toValue_string(numberToStringRadix(value, radix))
}