Read until a certain string is encountered..

        Args:
            s(bytes): The string to wait for.
            echo(bool): Whether to write the read data to stdout.

        Returns:
            bytes: The data up to and including *s*.

        Raises:
            EOFError: If the channel was closed.

def read_until(self, s, echo=None):
        """
        Read until a certain string is encountered..

        Args:
            s(bytes): The string to wait for.
            echo(bool): Whether to write the read data to stdout.

        Returns:
            bytes: The data up to and including *s*.

        Raises:
            EOFError: If the channel was closed.
        """

        s_len = len(s)
        buf = self.read(s_len, echo)

        while buf[-s_len:] != s:
            buf += self.read(1, echo)

        return buf