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: feature.go
    path of file: ./repos/godog/internal/models
    
    the code of the file until where you have to start completion: package models

import (
	messages "github.com/cucumber/messages/go/v21"
)

// Feature is an internal object to group together
// the parsed gherkin document, the pickles and the
// raw content.
type Feature struct {
	*messages.GherkinDocument
	Pickles []*messages.Pickle
	Content []byte
}

// FindRule returns the rule to whic
    
func (f Feature) FindStep(astStepID string) *messages.Step {
	for _, child := range f.GherkinDocument.Feature.Children {

		if ru := child.Rule; ru != nil {
			for _, ch := range ru.Children {
				if sc := ch.Scenario; sc != nil {
					for _, step := range sc.Steps {
						if step.Id == astStepID {
							return step
						}
					}
				}

				if bg := ch.Background; bg != nil {
					for _, step := range bg.Steps {
						if step.Id == astStepID {
							return step
						}
					}
				}
			}
		}

		if sc := child.Scenario; sc != nil {
			for _, step := range sc.Steps {
				if step.Id == astStepID {
					return step
				}
			}
		}

		if bg := child.Background; bg != nil {
			for _, step := range bg.Steps {
				if step.Id == astStepID {
					return step
				}
			}
		}
	}

	return nil
}