'As for L{OpenSSHClientTestCase.execute}, except it runs the \'conch\'
command line tool, not \'ssh\'.'

def execute(self, remoteCommand, process, sshArgs='', conchArgs=None):

    if (conchArgs is None):
        conchArgs = []
    process.deferred = defer.Deferred()
    port = self.conchServer.getHost().port
    cmd = ((('-p    {}    -l    testuser    --known-hosts    kh_test    --user-authentications    publickey    -a    -i    dsa_test    -v    '.format(port) + sshArgs) + '    127.0.0.1    ') + remoteCommand)
    cmds = _makeArgs((conchArgs + cmd.split()))
    env = os.environ.copy()
    env['PYTHONPATH'] = os.pathsep.join(sys.path)
    encodedCmds = []
    encodedEnv = {}
    for cmd in cmds:
        if isinstance(cmd, unicode):
            cmd = cmd.encode('utf-8')
        encodedCmds.append(cmd)
    for var in env:
        val = env[var]
        if isinstance(var, unicode):
            var = var.encode('utf-8')
        if isinstance(val, unicode):
            val = val.encode('utf-8')
        encodedEnv[var] = val
    reactor.spawnProcess(process, sys.executable, encodedCmds, env=encodedEnv)
    return process.deferred
