anchor.diff:  functioncallStatAssignOneReturnParamAsDecl returns [StringTemplate code=template("call")]
   {StringTemplate f=null;}
       :
  -        f= singleReturnParameter { code.setAttribute("outputs", f); }
  +        f= singleReturnParameterMandatoryType { code.setAttribute("outputs", f); }
           ASSIGN
           functionInvocation[code]
       ;
  
positive.code:     :  code=ll1statement
      |  (functioncallStatNoAssign) => code=functioncallStatNoAssign
      |   (functioncallStatAssignManyReturnParam) => code=functioncallStatAssignManyReturnParam
      |  (predictAssignStat) => code=assignStat
      ;
  
  
negative.code: 
  assignStat returns [StringTemplate code=null]
      :
      (  (functioncallStatAssignOneReturnParamAsAssign) => code=functioncallStatAssignOneReturnParamAsAssign
      |  (variableAssign) => code=variableAssign
      )
      ;
  
  