[From string (line 15) ]                                                               
                                                                                       
@startuml                                                                              
!unquoted function $dump ()                                                            
!$data={"participants" :[                                                              
{"id": "cm" ,"label": "customer master","desc": "manages customers"},                  
{"id": "tm" ,"label": "transaction manager","desc": "manages transactions"},           
{"id": "am" ,"label": "account master","desc": "manages accounts"}                     
]}                                                                                     
                                                                                       
':dump data;                                                                           
class dump {                                                                           
!foreach $part in $data.participants                                                   
   + $part.desc;                                                                       
!endfor                                                                                
}                                                                                      
!endfunction                                                                           
^^^^^                                                                                  
 This function does not have any !return directive. Declare it as a procedure instead ?