<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def export_env_string(name, value):
 # type: (AEnvName, AEnvValue) -> ADefine """Exports an environment variable with the given value"""

    os.environ[name] = value
    return Define(name, value)