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: template.go
    path of file: ./repos/goreportcard/vendor/github.com/alecthomas/template
    
    the code of the file until where you have to start completion: // Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE fi
    
func (t *Template) associate(new *Template, tree *parse.Tree) (bool, error) {
	if new.common != t.common {
		panic("internal error: associate not common")
	}
	name := new.name
	if old := t.tmpl[name]; old != nil {
		oldIsEmpty := parse.IsEmptyTree(old.Root)
		newIsEmpty := parse.IsEmptyTree(tree.Root)
		if newIsEmpty {
			// Whether old is empty or not, new is empty; no reason to replace old.
			return false, nil
		}
		if !oldIsEmpty {
			return false, fmt.Errorf("template: redefinition of template %q", name)
		}
	}
	t.tmpl[name] = new
	return true, nil
}