Returns PIDs of all processes with process name.
        If the process doesn't exist, returns an empty list

def get_process_pids(self, process):
        """Returns PIDs of all processes with process name.
        If the process doesn't exist, returns an empty list"""
        pids = []
        cmd_line_glob = "/proc/[0-9]*/cmdline"
        cmd_line_paths = glob.glob(cmd_line_glob)
        for path in cmd_line_paths:
            try:
                with open(path, 'r') as f:
                    cmd_line = f.read().strip()
                    if process in cmd_line:
                        pids.append(path.split("/")[2])
            except IOError as e:
                continue
        return pids