如何使用Objective-git从一些特定的提交中获取文件内容？

#import <ObjectiveGit/ObjectiveGit.h>

NSError *error = nil;
GTRepository *repository = [GTRepository repositoryWithURL:[NSURL fileURLWithPath:@"<仓库路径>"] error:&error];
if (error) {
    NSLog(@"创建仓库失败：%@", error);
    return;
}

NSError *error = nil;
GTCommit *commit = [repository lookupObjectByRev:<提交ID> error:&error];
if (error) {
    NSLog(@"获取提交失败：%@", error);
    return;
}

GTTree *tree = commit.tree;
GTTreeEntry *treeEntry = [tree entryWithPath:@"<文件路径>"];
if (!treeEntry) {
    NSLog(@"文件不存在");
    return;
}

GTBlob *blob = [repository lookupObjectByOID:treeEntry.GITObject.OID error:&error];
if (error) {
    NSLog(@"获取文件内容失败：%@", error);
    return;
}

NSString *fileContent = [[NSString alloc] initWithData:blob.content encoding:NSUTF8StringEncoding];
NSLog(@"文件内容：%@", fileContent);