func LoadData(path, pkg string, data []byte) (*File, error) {
	ast, err := bzl.ParseBuild(path, data)
	if err != nil {
		return nil, err
	}
	return ScanAST(pkg, ast), nil
}
func LoadData(path, pkg string, data []byte) (*File, error) {
	ast, err := bzl.ParseBuild(path, data)
	if err != nil {
		return nil, err
	}
	return ScanAST(pkg, ast), nil
}
// LoadData parses a build file from a byte slice and scans it for rules and
// load statements. The syntax tree within the returned File will be modified
// by editing methods.