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

def validate(identifier):
    '''Validate a source given its identifier'''
    source = actions.validate_source(identifier)
    log.info('Source %s (%s) has been validated', source.slug, str(source.id))