docs: def require(*reqs):
  	'''Require tasks or files at runtime.'''
  	for req in reqs:
  		if type(req) is str:
  			# does not exist and unknown generator
  			if not os.path.exists(req) and req not in GENERATES:
  				abort(LOCALE['abort_bad_file'].format(req))
  
  			# exists but unknown generator
  			if req not in GENERATES:
  				return
  
  			# exists and known generator
  			if req in GENERATES:
  				req = GENERATES[req]
  
  		if req.valid is None:
  			if len(req.args):
  				abort(LOCALE['abort_bad_args'], req, len(req.args))
  
  			req()
  
  		if req.valid is False:
  			abort(LOCALE['abort_bad_task'], req)