CreateAttachHandler is called from main for /api/sockjs.

WaitForTerminal is called from apihandler.handleAttach as a goroutine Waits for the SockJS connection to be opened by the client the session to be bound in handleTerminalSession.

SessionMap stores a map of all TerminalSession objects and a lock to avoid concurrent conflict.

TerminalMessage is the messaging protocol between ShellController and TerminalSession.

TerminalSession implements PtyHandler (using a SockJS connection).

PtyHandler is what remotecommand expects from a pty.