mime.go
func (mr *Reader) Get(ext string) string {
	var err error
	// No extension
	if len(ext) == 0 {
		return ""
	}
	// Strip the leading dot
	if ext[0] == '.' {
		ext = ext[1:]
	}
	mr.mu.Lock()
	defer mr.mu.Unlock()
	if mr.mimetypes == nil {
		mr.mimetypes, err = readMimetypes(mr.filename)
		if err != nil {
			// Using the fallback hash map
			if mime, ok := fallback[ext]; ok {
				return mime
			}
			// Unable to find the mime type for the given extension
			return ""
		}
	}
	// Use the value from the hash map
	if mime, ok := mr.mimetypes[ext]; ok {
		return mime
	}
	// Using the fallback hash map
	if mime, ok := fallback[ext]; ok {
		return mime
	}
	// Unable to find the mime type for the given extension
	return ""
}
func (mr *Reader) Get(ext string) string {
	var err error
	// No extension
	if len(ext) == 0 {
		return ""
	}
	// Strip the leading dot
	if ext[0] == '.' {
		ext = ext[1:]
	}
	mr.mu.Lock()
	defer mr.mu.Unlock()
	if mr.mimetypes == nil {
		mr.mimetypes, err = readMimetypes(mr.filename)
		if err != nil {
			// Using the fallback hash map
			if mime, ok := fallback[ext]; ok {
				return mime
			}
			// Unable to find the mime type for the given extension
			return ""
		}
	}
	// Use the value from the hash map
	if mime, ok := mr.mimetypes[ext]; ok {
		return mime
	}
	// Using the fallback hash map
	if mime, ok := fallback[ext]; ok {
		return mime
	}
	// Unable to find the mime type for the given extension
	return ""
}
// Get returns the mimetype, or an empty string if no mimetype or mimetype source is found