Channel for which the current sink chain is being constructed.
url
The URL of the object to connect to. This parameter can be null if the connection is based entirely on the information contained in the remoteChannelData parameter.
remoteChannelData
A channel data object that describes a channel on the remote server.
Return Value
The first sink of the newly formed channel sink chain, or null, which indicates that this provider will not or cannot provide a connection for this endpoint.