Gittern\Entity\GitObject\Commit::setSha PHP Method

    public function setSha($sha)
    {
        $this->sha = $sha;
    }

 public function hydrate(RawObject $raw_object)
 {
     $commit = new Commit();
     $commit->setSha($raw_object->getSha());
     list($meta, $message) = explode("\n\n", $raw_object->getData());
     $commit->setMessage($message);
     foreach (explode("\n", $meta) as $meta_line) {
         sscanf($meta_line, "%s ", $attribute);
         $attribute_value = substr($meta_line, strlen($attribute) + 1);
         switch ($attribute) {
             case 'tree':
                 $commit->setTree(new TreeProxy($this->repo, $attribute_value));
                 break;
             case 'parent':
                 $commit->addParent(new CommitProxy($this->repo, $attribute_value));
                 break;
             case 'author':
                 preg_match('/(.*?) <(.*?)> ([0-9]*)( (.+))?/', $attribute_value, $matches);
                 $commit->setAuthor(new User($matches[1], $matches[2]));
                 $commit->setAuthorTime(\DateTime::createFromFormat('U O', $matches[3] . ' ' . $matches[5]));
                 break;
             case 'committer':
                 preg_match('/(.*?) <(.*?)> ([0-9]*)( (.+))?/', $attribute_value, $matches);
                 $commit->setCommitter(new User($matches[1], $matches[2]));
                 $commit->setCommitTime(\DateTime::createFromFormat('U O', $matches[3] . ' ' . $matches[5]));
                 break;
         }
     }
     return $commit;
 }