code: function copyFromCopyRef($copyRef, $toPath)
      {
          Checker::argStringNonEmpty("copyRef", $copyRef);
          Path::checkArgNonRoot("toPath", $toPath);
  
          $response = $this->doPost(
              $this->apiHost,
              "1/fileops/copy",
              array(
                  "root" => "auto",
                  "from_copy_ref" => $copyRef,
                  "to_path" => $toPath,
              )
          );
  
          if ($response->statusCode !== 200) throw RequestUtil::unexpectedStatus($response);
  
          return RequestUtil::parseResponseJson($response->body);
      }
docs: Creates a file or folder based on an existing copy ref (possibly from a different Dropbox
  account).
  
  See <a href="https://www.dropbox.com/developers/core/docs#fileops-copy">/fileops/copy</a>.
  
  @param string $copyRef
  A copy ref obtained via the {@link createCopyRef()} call.
  
  @param string $toPath
  The Dropbox path you want to copy the file or folder to (UTF-8).
  
  @return mixed
  The <a href="https://www.dropbox.com/developers/core/docs#metadata-details">metadata
  object</a> for the new file or folder.
  
  @throws Exception