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/*
* Copyright 2017 Google
*
* 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.
*/
#import "FEmptyNode.h"
#import "FChildrenNode.h"
@implementation FEmptyNode
+ (id<FNode>) emptyNode {
static FChildrenNode* empty = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
empty = [[FChildrenNode alloc] init];
});
return empty;
}
@end
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