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: parser.go
    path of file: ./repos/devspace/vendor/github.com/Azure/go-ansiterm
    
    the code of the file until where you have to start completion: package ansiterm

import (
	"errors"
	"log"
	"os"
)

type AnsiParser struct {
	currState          state
	eventHandler       AnsiEventHandler
	context            *ansiContext
	csiEntry           state
	csiParam           state
	dcsEntry           state
	escape             state
	escapeIntermediate state
	error              state
	ground           
    
func (ap *AnsiParser) handle(b byte) error {
	ap.context.currentChar = b
	newState, err := ap.currState.Handle(b)
	if err != nil {
		return err
	}

	if newState == nil {
		ap.logf("WARNING: newState is nil")
		return errors.New("New state of 'nil' is invalid.")
	}

	if newState != ap.currState {
		if err := ap.changeState(newState); err != nil {
			return err
		}
	}

	return nil
}