<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def get_setting(self, name):
        notfound = object()
        "get configuration from 'constance.config' first "
        value = getattr(config, name, notfound)
        if name.endswith('_WHITELISTED_DOMAINS'):
            if value:
                return value.split(',')
            else:
                return []

        if value is notfound:
            value = getattr(settings, name)
        # Force text on URL named settings that are instance of Promise
        if name.endswith('_URL'):
            if isinstance(value, Promise):
                value = force_text(value)
            value = resolve_url(value)
        return value