In the Tutorials section - the Echo Server, HTTP Client, DNS Lookup, and TLS Context sections have the required includes and namespaces within the Note - which is fine.
In the Tutorials - Hash Server and Reconnect with Backoff sections the required includes and namespaces are outside of the Note.
Move the required includes and namespaces within the Note in the two tutorials mentioned above.
In the Tutorials section - the Echo Server, HTTP Client, DNS Lookup, and TLS Context sections have the required includes and namespaces within the Note - which is fine.
In the Tutorials - Hash Server and Reconnect with Backoff sections the required includes and namespaces are outside of the Note.
Move the required includes and namespaces within the Note in the two tutorials mentioned above.