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: strslice.go
    path of file: ./repos/werf/test/pkg/thirdparty/contruntime/strslice
    
    the code of the file until where you have to start completion: // THIS WAS COPIED FROM github.com/containers/image/v5/pkg/strslice

package strslice

import "encoding/json"

// StrSlice represents a string or an array of strings.
// We need to override the json decoder to accept both options.
type StrSlice []string

// UnmarshalJSON decodes the byte slice whether it's a string or an array of
// strings. This method is needed to implement json.Unmarshaler.
func (e *StrSlice) Un
    
func (e *StrSlice) UnmarshalJSON(b []byte) error {
	if len(b) == 0 {
		// With no input, we preserve the existing value by returning nil and
		// leaving the target alone. This allows defining default values for
		// the type.
		return nil
	}

	p := make([]string, 0, 1)
	if err := json.Unmarshal(b, &p); err != nil {
		var s string
		if err := json.Unmarshal(b, &s); err != nil {
			return err
		}
		p = append(p, s)
	}

	*e = p
	return nil
}