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: prompt_template.go
    path of file: ./repos/langchaingo/prompts
    
    the code of the file until where you have to start completion: package prompts

import (
	"errors"
	"fmt"

	"github.com/tmc/langchaingo/schema"
)

var (
	// ErrInputVar
    
func resolvePartialValues(partialValues map[string]any, values map[string]any) (map[string]any, error) {
	resolvedValues := make(map[string]any)
	for variable, value := range partialValues {
		switch value := value.(type) {
		case string:
			resolvedValues[variable] = value
		case func() string:
			resolvedValues[variable] = value()
		default:
			return nil, fmt.Errorf("%w: %v", ErrInvalidPartialVariableType, variable)
		}
	}
	for variable, value := range values {
		resolvedValues[variable] = value
	}
	return resolvedValues, nil
}