Check whether data can be written to a socket at the current time.
Return true if writing is possible, otherwise false.
This function allows you to check whether it is possible to write data to a socket right now.
If an error occurs on a system socket when executing the function, connection established via SocketConnect is discontinued.
The function can be called only from Expert Advisors and scripts, as they run in their own execution threads. If calling from an indicator, GetLastError() returns the error 4014 – "Function is not allowed for call".