/// <summary>
/// Perform a transfer.
/// </summary>
/// <exception cref="System.NullReferenceException">This is thrown if
/// the native <c>CURL*</c> handle wasn't created successfully.</exception>
/// <returns>The <see cref="CURLcode"/> obtained from the internal
/// call to <c>curl_easy_perform()</c>.
/// </returns>
public CURLcode Perform()
{
EnsureHandle();
return((CURLcode)External.curl_easy_perform(m_pCURL));
}