fix

pkg/schema/schema.go

@@ -47,7 +47,7 @@ func (s Schema) WithIncludes(includes ...interface{}) *Schema {
 
 func (s *Schema) WithMetadata(kv ...string) *Schema {
 	if s.Metadata == nil {
-		s.Metadata = make(map[string]string, len(s.Metadata))
+		s.Metadata = make(map[string]string)
 	}
 	for i := 0; i < len(kv); i += 2 {
 		s.Metadata[kv[i]] = kv[i+1]