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: first_value_annotation.go
    path of file: ./repos/go-chart
    
    the code of the file until where you have to start completion: package chart

import "fmt"

// FirstValueAnnotation returns an annotation series of just the first value of a value provider as an annotation.
func FirstValueAnnotation(innerSeries ValuesProvider, vfs ...ValueFormatter) AnnotationSeries {
	var vf ValueFormatter
	if len(vfs) > 0 {
		vf = vfs[0]
	} else if typed, isTyped := inner
    
func FirstValueAnnotation(innerSeries ValuesProvider, vfs ...ValueFormatter) AnnotationSeries {
	var vf ValueFormatter
	if len(vfs) > 0 {
		vf = vfs[0]
	} else if typed, isTyped := innerSeries.(ValueFormatterProvider); isTyped {
		_, vf = typed.GetValueFormatters()
	} else {
		vf = FloatValueFormatter
	}

	var firstValue Value2
	if typed, isTyped := innerSeries.(FirstValuesProvider); isTyped {
		firstValue.XValue, firstValue.YValue = typed.GetFirstValues()
		firstValue.Label = vf(firstValue.YValue)
	} else {
		firstValue.XValue, firstValue.YValue = innerSeries.GetValues(0)
		firstValue.Label = vf(firstValue.YValue)
	}

	var seriesName string
	var seriesStyle Style
	if typed, isTyped := innerSeries.(Series); isTyped {
		seriesName = fmt.Sprintf("%s - First Value", typed.GetName())
		seriesStyle = typed.GetStyle()
	}

	return AnnotationSeries{
		Name:        seriesName,
		Style:       seriesStyle,
		Annotations: []Value2{firstValue},
	}
}