add scheme builder

pkg/runtime/scheme_builder.go

+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package runtime
+
+// SchemeBuilder collects functions that add things to a scheme. It's to allow
+// code to compile without explicitly referencing generated types. You should
+// declare one in each package that will have generated deep copy or conversion
+// functions.
+type SchemeBuilder []func(*Scheme)
+
+// AddToScheme applies all the stored functions to the scheme.
+func (sb *SchemeBuilder) AddToScheme(s *Scheme) {
+	for _, f := range *sb {
+		f(s)
+	}
+}
+
+// Register adds a scheme setup function to the list.
+func (sb *SchemeBuilder) Register(funcs ...func(*Scheme)) {
+	for _, f := range funcs {
+		*sb = append(*sb, f)
+	}
+}