'Create a process with the command line \'cmd_line\' and environment
\'env\'. Stores the pid of the child process in the \'pid\' attribute.'

def _start_process(self, cmd_line, env):

    app_name = None
    command_line = cmd_line
    process_attributes = None
    thread_attributes = None
    inherit_handles = 1
    creation_flags = win32process.CREATE_NO_WINDOW
    new_environment = env
    current_directory = None
    proc_args = (app_name, command_line, process_attributes, thread_attributes, inherit_handles, creation_flags, new_environment, current_directory, self._si)
    proc_handles = win32process.CreateProcess(*proc_args)
    self._pipe_stdout.close_filehandle()
    self._pipe_stderr.close_filehandle()
    (self._hProcess, self._hThread, self.pid, self._tid) = proc_handles
