func (r *Rule) SetPrivateAttr(key string, value interface{}) {
	r.private[key] = value
}
func (r *Rule) SetPrivateAttr(key string, value interface{}) {
	r.private[key] = value
}
func ( r * Rule ) SetPrivateAttr ( key string , value interface { } ) { r . private [ key ] = value }
// SetPrivateAttr associates a value with a key. Unlike SetAttr, this value
// is not converted to a build syntax tree and will not be written to a build
// file.
SetPrivateAttr associates a value with a key . Unlike SetAttr this value is not converted to a build syntax tree and will not be written to a build file .