/// <summary>
/// Read/write data to/from each CurlEasy object.
/// </summary>
/// <param name="runningObjects">
/// The number of <see cref="CurlEasy" /> objects still in process is
/// written by this function to this reference parameter.
/// </param>
/// <returns>
/// A <see cref="CurlMultiCode" />, hopefully <c>CurlMultiCode.Ok</c>
/// </returns>
/// <exception cref="System.NullReferenceException">
/// This is thrown if the native <c>CurlMulti</c> handle wasn't
/// created successfully.
/// </exception>
public CurlMultiCode Perform(ref int runningObjects)
{
ensureHandle();
return(NativeMethods.curl_multi_perform(_pMulti, ref runningObjects));
}