/// <summary>
/// Add an Easy object.
/// </summary>
/// <param name="easy">
/// <see cref="Easy"/> object to add.
/// </param>
/// <returns>
/// A <see cref="CURLMcode"/>, hopefully <c>CURLMcode.CURLM_OK</c>
/// </returns>
/// <exception cref="System.NullReferenceException">
/// This is thrown if the native <c>Multi</c> handle wasn't
/// created successfully.
/// </exception>
public CURLMcode AddHandle(Easy easy)
{
EnsureHandle();
IntPtr p = easy.GetHandle();
m_htEasy.Add(p, easy);
return(External.curl_multi_add_handle(m_pMulti,
easy.GetHandle()));
}